Cat 315cl--3644 hours--serial # cjc02070-- Have had it at hydraulic shop, one cat dealership, no one has figured it out yet, I owned diesel shop for 40 plus years and have not figured it out, will pay someone to figure it out, will give as much info as I can and maybe someone has run into this before. Started with pump howl when stick out function was opened, got worse as day went on, shut down and changed all three hyd filters and cut open and all three looked good, babied thru day finished customers job, had the pro's look at it and they are baffled, here is the current condition, put bucket on ground front of machine hit stick out and no power and pump howl, pull stick in some power and less howl, all these test are performed at full throttle, engage left track forward or reverse and split second howl then normal operation both directions, open right track no howl and normal operation, swing no issue, boom up is fine, here comes the stumper, put bucket on ground in front of machine put pressure and machine will only rise about 4 inches no pump engine strain, if you open stick out function with boom down function still full open unit will leap 4 foot in air, if you pull stick back it will not effect boom function, changed alt control function valve and does same in either pattern, ---so have pump howl and weak power on stick out--- weak an light howl on stick in--weak power on boom down unless stick out function is opened then normal power--how is stick function effecting boom down pressures? I pulled on wrenches old school way, have had a lot of ''could be'' change this change that etc, do not want to throw parts at it, have had cycle times checked, pump pressure is normal, tracks straight in line, main relief valve rebuilt, but no one can tell me the problem,I do have cat ET and no codes showing , any and all help would be appreciated and gladly paid for, 67 year old mechanic could use some help
Well, this is a bit confusing! LOL I have a couple of questions...………...what is the hydraulic temp running? Have you taken the lines off the stick cylinder itself and run a pressure test in both directions by plugging the lines? When the pump starts this howling is there any other effects on the hydraulic system? Have the tubelines been checked to make sure one isn't crushed or bent restricting flow? It sounds as though the problem is in the stick circuit, but when engaging other hydraulic to trouble shoot it, it becomes confusing because of the way the machine acts. I would personally eliminate the stick circuit completely. Someone else will come along with other ideas Im sure.
Excellent response!!!! I clear land and bucket/rake spends it's time in the trees, i will go check hard lines, never gets over halfway up on hyd oil temp except in summer with air on, I watch it close, turn air off and slow up when starts to climb, will get fittins to put gauges on hyd lines and plug, your saying pressure test each one for matching pressures correct? Again good idea, old is only excuse I have lol
This is over my level, I only understand simple hydraulics, and simple manufacturers. If I was tackling this, I'd buy the manual first thing, then study how the system works. Best few hundred dollars and a day's time you'll spend. Then you'll have a logical place to start looking. My guess is you'll find something simple in the pump/valve control area, since the functions will work if you scratch your head right.
More info after testing, took cap off hyd tank and pressure tested, will only hold 2 lbs, put new 10lb cap on and ran machine, hyd power a lot better than before but still some howl, now wondering if pressure pump for tank is weak, there seems to be 2 issues, may be cavitation from lack of tank pressure to feed pumps, second is the cross flow of functions, did not try before but with bucket down in front of machine and push boom down to full open will raise machine 4 inches and if you hit curl it shoots unit in air , so stick out and curl send pressure to boom down, have run into resolvers doing this on backhoe you open one function and no pump spool then bump another function you get full pump spool, guys at cat said this system is negative flow and is different, thanks Mr Delmer for responding
First, do you have a pattern change valve. Some excavators have them. If you do, make sure your lever is all the way one side or the other. I had one in the past with similar issues. What pattern are you using JD or ISO? In other words, are swing and arm on the same stick, while boom n bucket on the right? If so , if you dig teeth in the dirt, and attempt to swing, will it howl as well? When you curl your bucket, you're stroking the other pump up and through the miracle of the center passage (not the turning joint) get the oil to your arm. I suspect that your one pump has a weak controller. In the past , I have swapped controllers. It's not something to jump into lightly, lots of bejeezus parts to jump out if you're careless. Since you track straight, pump is likely not hurt badly. Most importantly, does your swing act as your arm function.
A little more to look at
What about the state of the suction hose from the tank to the pump inlet side..?
Isn't that a common feed to both pumps? I thought the same, but then I thought they were common? I'm not sure, not my primary product.
Me neither, but any time a pump's screaming the first place I think to tick off the diagnositc list is the suction side. Many years ago an old technical instructor gave the class some wise words about hydraulic system diagnostics - "Follow the oil. Where does it start its jounrey.? That's right - the tank. Well that's where you should start your diagnostic journey, from the same place as the oil. Maybe a large part of it will be a box-ticking exercise, but following the oil will get you to the root cause every time." Those words make just as much sense now as they did when I heard them for the first time.
WOW, thanks everyone for the response and taking time to assist, does have pattern change, went there first, run with left stick swing stick function, right stick boom an bucket, change pattern the issue follows, hold boom down full throttle stick out and curl up both increase boom down function pressure, if I swap pump controllers [gulp] will the weak controller not cause other control issues? What you say makes sense b/c when this started [had wife [she runs excavator most time an I run dozer,] hold function and make pump howl sounded like was right pump standing facing pumps, put gauge on and left pump hit 5k, right pump started up bam dropped to 2k, pilot pressue 900 <---- mom/pop operation lol
Here's what I would do before I opened a pump. Raise one side off the ground. Paint one track pad a visible color. Have your wife run the track full throttle in rabbit. You time the track, disregard first revolution when colored pad comes around start timing 3 full revolutions. Write it all down. Left track fwd, rev, in turtle and rabbit. Then do the same with the right. Your looking to see that they're dead even. It's kinda like a poor man's flow meter.
It would be unusual to have a pump problem with those amount of hours, but it can happen. I have seen the nut on cylinder rods come loose and allow oil to rush past the space between the nut and the inside of the piston and cause that kind of noise. As I recall that machine is two pump flow for all the implement functions so for everything else to work normally would indicate the problem being in the stick circuit. funwithfuel is correct in suggesting doing cycle times to try to narrow down the issue. What has been done to actually confirm that the noise is from the pump? Does the pump vibrate at the same time as the howl occur? Has the pump suction strainer been pulled and inspected? Are there any codes showing on the monitor panel?
scan with et no codes, tracked it in 150 foot pattern forward and reverse no drift either direction, cat did a clycle time test on boom functions all was good, have not pulled fluid and checked strainer, after replacing pressure cap I have more power but still have function crossover issue, old tank cap held 2 lbs put new 10lb on, standing at pump and opening function to make pump squall sounds like is right pump facing the pumps
If it’s any help I can post a full System Operation document for the Hydraulic System. Here's the Hydraulic Schematic for now. TBH I scanned through it and it made no mention of the tank being pressurized to aid pump suction.
Here's the System Operation for the hydraulic system. Regarding the pressure cap on the tank, it is listed as such, but no specification regarding what pressure it's supposed to be.
cat says 7-9 thank you sir
bucket on ground in front of machine with light pressure down, hit stick out to make pump howl both pumps show and hold 4900 pounds, guess will drain tank and see flow to pumps restricted
You see same pressure at both pumps? Yet pump(s) howling? How did the track test go? How are you seeing pressure, physical gauges, pressure transducer on display, measuring at the pump? Just trying to see what you see . Have you the means to measure milliamps across a pwm valve? Let's go back and revisit when you said you swapped out the hydraulic filters. One should have been a large diameter spin on. You found nothing in that one, not in the oil or the media?
Reviewing the schematic Nige was good enough to upload. AA feeds your stick until the demand is great enough, BB joins in through stick2 spool. Stick2 us dictated by boom priority pressure reduction valve. I suspect that valve may have a bit of debris in its seat preventing you from getting stick 2 oil to stick spool. Did you dig the teeth in and try to swing, was the howl there or not?
test results, teeth stuck in ground, stick in has power and medium howl, stick out has very very little power and loud howl, swing left or right has howl but no ways as loud as stick out, more than normal though, and yes big thanks to Mr. Nige for the info, been studying it, liquid filled 10k pressure gauge, going drain tank an pull screen in morning to eliminate supply questions, guy at cat told me #2 boom spool also, is that the one on page 9 #18 on schematic Mr. Nige sent? Lord this stuff was easier 20 years ago lol
It wasn't easier, our eyes just worked better. Dont confuse boom 2 with stick 2 . Stick 2 gets oil from pressure reducing valve at boom priority valve. If that valve sticks open it drains the oil off , effectively neutralizing the spool and bleeding servo to stick. Either way, based on your results. I'm leaning hard towards regulator. I think your pump is stuck in Q-min . It's a bit difficult to troubleshoot a negative control system with the regulator controlling leak to tank. The best I could suggest would be to swap the pigtails from AA to BB. You would be stuck in Q-min in all but boom and stick and straight line travel if you have it. If the problem follows the pigtail, its electrical, if it stays, you're probably going to be looking at the regulator. Good luck and be careful, things are getting into the area where bad things can happen quick, if you dont think things through.
do not understand Q-min, facing pumps from ground are what you are calling regulators the valve with pigtail harness? so swap them?
Sorry, Q-min means minimum displacement. Yes, swap pigtails only, see if it follows. If that doesn't get it, we'll look at swapping regulators. I'm really surprised none of the CAT guys other than Nige have jumped in. BTW , I tend to lose sight of the obvious. You may want to follow his advice, follow the path of the oil. Start at the suction strainer.
You have an arm regeneration valve that allows some of the return oil from the rod side of the cylinder to go into the piston side of the cylinder to prevent a suction on that side when quickly pulling the stick in. It also stops the lag you used to get on older machines when the stick got to the vertical point in its travel inward. There is a possibility that the spool is stuck and is something to check. If it is stuck I could see it causing noise because oil would be fed to both sides of the cylinder if stuck in stick in position. I see the spool in the schematic but don't know where it is on the control valve. The other valve to check would be the load lock valve or anti-drift valve as they call it on the rod side. Since you have noise with no debris you have what we call a gremlin. They take time to find and usually cost a fair amount of money trying to identify it but when done you will be tapping yourself on the head that it shouldn't have been that hard to find. Sometimes they go away and you never know for sure why.
thanks to everyone and will do as you advise and start with strainer and the aa--bb then stick 2 then anti drift, learned a long long time ago not to whine just step up and handle what is necessary but at almost 70 whining sure looks god lmao
cleaned screen then thought thiis video of what unit is doing may help
In the second video, what function are you pulling to get that reaction. I only "see" the left hand pump stroking up. I watched it several times. You can see your load sense line stiffen up as well as pump discharge off the top. The right side doesn't behave the same. The first video really illustrates what challenges you're facing. Do you have enough harness to swap pigtails from aa to bb. In the video, it looks like a challenge.
The other thing I see in the video is that boom down struggles until you bring in extra oil from the arm circuit. Is that a fair statement?
What strike me is the boom continuing to go down after letting go of the stick function. Are you still holding the boom down at the same time. The noise sounds like a heavily loaded pump and not a broken pump. "Gremlins"
Yes holding boom down and bumping stick out, then hold boom down and give it full stick out, yes boom struggles til hit stick out or bucket curl, stick in or bucket out does not add pressure to boom down, just got in been on dozer all day, doing stick out in the pump video , makes loudest noise
will go try AA to BB, if not long enough will adapt
Ok test results, switched AA-BB, more down pressure for sure, open function raise about 2 foot then hold function full open will struggle and creep up with very very very little pump noise then hit spot and climb way up, still have all functions and opening ftick out will still greatly assist boom down, but changing AA-BB gave more down boom pressure,
stick out still howls bad
pilot pressure is 900, cat says 595 is this part of problem?
Sounds like it. Perhaps a drainage issue. 900 , no functions pulled safety lever engaged?
no functions pulled don't remember about safety lever but will check, just switched AA-BB back and unit goes up with boom down function, not great but better than 4 inches it was doing, will rise all way without stick out assist, Cold oil? will get back off job tomorrow and work it and get op temp and check pilot with lever down and report back
Wher AA and BB hook up are those pressure sensors?
No, it isn't right. Has anyone been tampering with it? Wrong pilot pressure can cause all sorts of weird problems. I would; A. Verify your gauge is correct. B. Change the pilot filter. C. If it's still high, adjust it.
Have changed filter, owned for year and half no issues, will change to another gauge and retest tomorrow
Cat 315cl--3644 hours--serial # cjc02070-
AA-BB are pressure regulators. They keep you from bogging the engine down. As engine rpm drop, the valve allows more control oil in to destroke the pump keeping rpm in power band. The exact opposite of how you would think. That servo pressure is a big issue. I don't think I've ever experienced that, but have heard stories.
open door behind cab are there solenoids behind that panel u have to remove panel get someone to operate machine and listen ...its center of machine but panel needs removed ..cat 315 cl have a ground issue with solenoids test the wires open ground ...mine is cjc01986 had bad ground and machine wouldn't move nothing but crank ...pin poke and test the grounds wires see if it sound changes ….send me 250 if it fixs problem ill send u some deer jerky
true, ran external ground strap right after i got machine had ground issue with swing/implement solenoid on pump, you are talking about panel fuse box mounted to right?
Truecountry thanks for taking time respond, and about the 250? whoever tells me how fix this blank blank unit I will roll around on the ground laughing and send them 500 for a pack of jerky and be tickled be because I got a bargain, man take time to help me I sure take time to help him, been comission mechanic all my life and got paid for what I did,
Just adjusted pilot pressure down to 600, still cross feeding and same stick out howl, backed out 1 full turn on pressure regulator, took it off and apart seat and o ring looked fine no trash
Going by the videos I hear worn piston slippers causing chatter on one pump in the second video. On the first video what you are seeing is not that uncommon. As the boom goes down it comes to a point where either the tracks have to move or the stick has to move to release the binding. Try moving the tracks or rolling the bucket and I think you’ll see the boom move also.
I see you've been busy. While you had the regulators off, did you consider swapping them? A to B ? Mobiltech is correct in that sometimes you have to track fwd/rev to allow boom to continue traveling. That said, it looked like you were in soft forgiving material. To me, it sounds like one pump is working its butt off and the other is kinda hanging back, which falls into why, when you touch arm while booming down the thing suddenly comes alive. It just kicks in all of the sudden and with authority.
I think you got something limiting your Boom 2 spool. Is it possible to pull the cap and inspect. I know we're all asking a lot. I also realize it's no walk in the park. You may have a centering spring that's come loose and not allowing the spool to return to center. Worth a look. I attached a copy of the schematic . I outlined the flow of oil back to the boom 2. I think the demand from the stick is pushing the logic valve open to allow Boom 2 to join in with Boom 1. You might also want to look at the small spool in the illustration A , make sure that little shuttle is free. I suspect that is the one that allows one drain oil from Boom 2 to drain off and shift the spool. if the drain is blocked the spool cant shift.
I think your right, put teeth in soft sand and try stick out it has way way less power than it has always had, did not think about swapping just changed the wires, Mobiltech what are piston slippers? Is that the loose cup on end of rod that slides in/out of cylinder on pump? Just curious, Funwithfuel do you have a picture location for us old folks on the valve you want me to pull? Been on dozer all day, brain dead, will pull boom2 first? Or swap regulators first?
I sure dont. Sorry. I should think the ports would be identified by alpha numeric characters cast into the valve body. aL2 should be the spool identifier. I have clipped a section from the material Nige posted. It gives a pretty clear description of what is happening where. The smaller spool or passage as it is referred to should be adjacent to the spool cap . Should just be a couple screws to remove . Remove the end cap/plug to access spool. You may not even need to remove, you may be able to just shift it side to side. Bottom line, make sure its not bound up. In the second image , it shows the basic components of a piston pump. What Mobiltech is referring to are called out as piston shoes, I believe. Everyone calls em slippers. #1 point of failure of a piston pump.
I'm 90% sure the highlighted housing in the image is where you want to look. In the past, I have encountered where fittings in a body have scarred the spool to where it eventually seized. A little grinding, a little polishing of the spool and all was right with the world. I hope this shows something.
yep that is what i thought, thanks, may be back off dozer in time tomorrow to start looking at valves, should I swap regulators first ? or just get into valves? And yes what you sent will get me started thanks
I'd look at the spool in the small housing first. Pull spool caps and check centering springs second. Regulators third. Be as clean and careful as humanly possible.
When you move spools, oil will come out if your implements are not completely neutralized. Be extremely careful please.
yea always kill engine key back on, move everything bleed off pressure thanks
Take the cap off the hydraulic reservoir as well before you bleed off the pressure in the circuits.
9 psi can make quite a mess.
Both those and the radiator caps never held any pressure. It might say nine but I've yet to find a used one that held more than five on a Cat excavator. Most I've tested were around two. Even so you will stay cleaner by taking it off.
I am in on that lol thanks.
Yes that is the piston slippers in the pump that I’m talking about.
see i learned something, thanks mobiltech, just got in going to pull valves first thing in morning, taking day off see get this thing fixed
Question, have boom 2 spool out, looks good no scars etc, inner spring on top is loose inside outer spring, 3/16 free travel with left eye closed, is this so when outer spring is collapsed it will take up slack and hold valve in correct position in body?
Pulled more spools and all same so now I know, may have found the problem, no that is wrong, may have been''' directed ''' to the problem will know in couple hours, will post results one way or other
Both springs should be tight. They're there to absolutely center that spool in the valve. If they are not, the spool is essentially moving around. Dont mix up the spools either. They all have their own home.
boom spool 1 boom spool 2 both have slack on inner spring, pulled little valve and thought it was stuck, cleaned lubed and moves freely put together thinking what a hero I was an no difference, swapped regulators and no change, pulled little valve thinking need make sure not stuck, took apart and moves free free, now question, air up either line no air comes out anywhere, air small bottom holes and air comes out the other hole, air right hose fitting can hear/feel valve shuttle air left hose fitting nothing , no air ever comes out bottom holes, take apart and air goes thru lines into chamber shouldnt air cone out bottom holes???
yes same spool back in same hole lol checked allen head bolt still tight on boom spools when I pull the two screws pulling cap off spool there is no tension against cap it sits flat on valve body, should it rise up some as you pull screws? trying give you as much info as I can to help you kinda be here
Only the shoulder of the cap should have any tension, just against the sealing ring. So, yes, you should be able to take the screws out and not have the cap move. In regards to the air flow. I personally am at a bit of a loss. I , like you, believe it should go both ways. I see no check valve in the schematic regarding that shuttle/ housing.
should I pull outer spring and make inner longer ? that way on one and two boom spool, more so on #2
Why don't you buy one of each and compare them against yours? Bob
good idea thanks Bob, I think they are an assist spring for the outer spring, like outside collapse to certain point then it hits second spring, but I do not know that, if was only one spool would call it bad but both spools have loose springs,
One spring pulls, the other pushes. They work together to keep you centered. Dont change anything by lengthening or trimming. Like Bluox said, compare but dont alter.
Just pulled a stick spool and it is same way inner spring is like the others so where do I go now? If a pressure regulator was dropping pressure would it set a code? I have ET and have scanned and there are no codes
A quick and dirty way to eliminate the electrical side as a problem is to activate the backup switch on the rear of the right armrest. This will kill power to the EPC (engine pump control) and supply a fixed current to the PRV. See if that alters your symptoms in any way.
Then I would guess, that's the way it has to be. Unfortunately, I don't know where else to look. Based on schematic. I'm still troubled by the passage you mentioned earlier only flowing one way
Already did and it does same thing, thanks for advice it is 100% appreciated !!!!!
I wasn't going to say this earlier because I'm not keen on making a comment unless I'm fairly sure of myself, but seeing as we now seem to be at the guessing stage, here goes. There are two check valves in the return lines, called the slow return and bypass. Now on the B series excavators the slow return valve could work loose and cause a partial blockage giving weird intermittent power and noise issues. I haven't come across the same problem on the C series, but your symptoms kinda sorta match. I think you would have to drain the tank to get them out.
If your standing in front of valve body looking down at valve the line going in right side will move spring loaded valve to left, line on right ''I think""" holds valve closed, spring pushes it to right,, with it this way the two bottom ports are an open passage ie free flow, I bet when line on right pushes valve to left it shuts off the free flow, blew air into passages in valve block, one way gets your face full of oil, other way makes valve in body click lol Cat 315cl--3644 hours--serial # cjc02070
BTW Cmark, your avatar says EXACTLY how I feel after a day of this excavator lol crown black sure gonna ease some bones been up/down that sucker 100 times today
Lol. You can stop posting your serial number now! That's my signature and appears at the bottom of all my posts as a reminder to members less diligent than yourself.
22 January 2019 06:42 catmastertech Mechanic The centering springs of the spools are two springs and one is loose. This is for modulation control of the spool. Low pressure compresses the outspring and as pressure increases, the second spring is compressed and is modulating to prevent the spool moving too fast. Got this response from guy on justanswers
Cmark, found valve and will be day or two but will drain tank and pull, looks like fun getting in there lol
Cmark, have not gone away, have to run dozer and will get back on the excavator project, funwithfuel said he was out of ideas so like you say it is ''guess & try'' time now, if it is pumps will put one on and cringe if it does not cure issue, going to drain tank and pull belly pan and side engine cowl to get in to the slow return, read some threads and they all say it ''backed out'', what am I looking for when I get it off? check ball? adjustable check ball? Tried the experts on justanswers and they gave up, would pay good money to someone who could get this thing straightened out,
This is what it looks like on your machine. And this is what the B series looks like On the B series, snap ring 3 would come adrift and the valve 2, which is actually threaded into the housing, would unscrew itself. As I say, I've never seen this failure on a C series, but you never know.
Thank you very much sir
Cmark, have not puller valve yet, clumsy fell off track and tore knee up, will pull valve first of week and get back with you,
Hey, no panic. I'm here eight days a week
Product Support = 26 hours/day, 9 days/week ........ The customer never calls the Sales guy at 3am, he calls Product Support. Been there, done that.
I made sure all my customers knew the first person to call was the sales guy. The earlier the better and don't stop at just one call.
New clue, line at back of pumps goes to filter that is mounted next to pilot pressure filter, goes from this filter to tank, some kinda pump bypass am guessing, this filter blows wide open if engine half throttle an boom up or stick in is pulled an held, bump either function an get shudder let off does not blow if do it quick, pulled line from filter to tank an get good hyd oil flow from tank, have experimented with 3 new cat filters getting info, have been experiencing pump pressure loss is this the issue an now enough pressure escaping to bypass to blow filter? Pressure regulator hung open?
That's your case drain. Pump or motor issues are only cause for that filter to rupture. But I remember you saying you replaced all early on, correct?
Correct
I would venture to guess, one pump is hurt. When you swapped regulators, did you verify the pin dropped into the yoke?
Explain
I pulled electronic switch out an swapped
I am not 100% familiar with your pump regulators, but typically it would be a pressure and flow compensating regulator which would have some type of mechanical influence on the swash plate. It is sometimes a pin in a hole or a clevis or sometimes it is just a hydraulic passageway that acts on a piston in the pump body.
Just saw the reply. Not a problem.
Then, I think your problem has finally showed its ugly head. You have a pump that is hurt. If you take each hose away from the filter head and into a bucket, you would see a higher volume from one or the other. The higher volume obviously being the problem child
Before jumping to conclusions, you should take a step back, review everything you have done, is it back to original? What has changed? What testing procedure has not been restored to original configuration? If everything is back the way cat built it, your pump is hurt. Being an integral unit doesn't help either. Wish I had better news.
Isn’t this machine have Rexroth bent axis pump? Which case drains in to suction?
I did not pull mechanical pressure regulators, just electronic ones u had me switch wires then regulators
Both pumps tested 4860 lbs with manual gauge an open function held that pressure
Is the pump howling when you operate functions that on one joystick but not the other? Better yet is pump howles when you operate functions that on the same section of main control valve?
What are the pressure readings of pilot and negcon lines when pump howles?
What are the pumps pressure at “howling”?
Want to ask more experienced people: can modulating port relief valve create howling sound in the pump?
I am not smart enough to know problem only provide info so those who do know can make decision, if pumps bad will replace,
Pilot pressure was 900 cat said turn down to 600 so I did that, pumps never dropped at howl,
Read pumps pressure at deadheaded stick out and stick in. Deadheaded means against end of the cylinders travel.
Can't now will blow filter
U see video of pumps howling? Started in stick out only, then went to boom down no power pick up how, hit stick in with boom down full open would shoot machine in air, cross feeding video will show you is on this thread
So, do pumps howling only in combined operation ( boom and stick) or in single - stick in also?
Started with Single stick operation of stick, weak power.
When this started it was like a backhoe I had one time, you pull boom up lever and no power because pump would not spool up, open another function and would have boom up power, pump would spool up. Was the resolver. This unit, push boom down, full throttle would raise machine 6 inches. Bump stick in and boom would have a lot of power and raise machine 4 foot in air as the video showed. Cat dealer gave up and said run it.
And now, is it weak in both directions, stick out and stick in? Or just a stick out. I’m asking this because each port has its own pressure relief valve, if you OK on stick in that might be the reason. Also John said about regen circuit. The control valve is not that far away from the pumps, and it’s on the right side of the pumps. The noise might come from there but sounds like it is in pump compartment.
Pulled stick 1 and stick 2, boom 1 and boom 2 spool and checked to see if they were free. Functions same in and out. Hard to check now because you can only bump stick for a second or it blows filter. Can only raise boom 6 inches at a time or filter will explode.
What filter does it blow?
Case drain
Then it is 99% your pump is done for!!! Sorry!
No prob thx
Also check the passage from case drain filter to tank together with tank pressure/vent valve, even with high case drain flow it is not supposed to create that kind of pressure!!! High case drain pressure is number one reason for “shoe/piston lift”!
Is that filter for pumps drain only, and everything else drains through return filter?
Where in Florida are you? If around Pensacola I can come with analyzer and test run those pumps! That’s a lot of money, you need to be 100% sure before condemning them! I’m in Mobile
In Chiefland,
Gimme couple hours on dozer right now, will sure have u come look
That’s 380 miles. It’s too far.
This is one of the few cat excavator pumps with a case drain line. I had to look it up to be sure. If you have high case drain flow the pump is the problem . After case drain test pull the pump and take it apart. Look and see what is failing .It will probably need a reman but at least you will know what happened. These pumps arent that hard to work on .
Although it’s still something “fishy”, with that amount of bypass leakage the pump should not build up 4600 psi pressure.
Yeah, I was looking at it on the video - and it’s definitely not A8VO! Do you know the model of it?
Where best place buy a pump? Cat is $6,200
pump number is--- 176-3963 on tag on pump
there is another line coming into case drain line right before filter
Where does it come from? Probably center pivot and another branch from swing motor.
will be back up there tomorrow and will look
if I turn key on and have someone pull levers in forward travel cal i pull it short ways to shop? I know if you turn key on and move joysticks it will release pressure allowing boom down etc, need to move it and do not want to blow any more case drain filters
I don’t think there will be enough pilot pressure to release both parking breaks and move the spool at the same time!
Gonna have to pull final drive cores.
will do thank you
Or if you do have some kind of portable hydraulic unit just connect it to pilot pressure diagnostic nipple, it’s PD quick connect style
machine will run and has pilot pressure just when u open a function it blows filter, does not blow filter if you curl bucket but travel boom and stick does
Probably empty bucket does not create enough pressure to set off huge bypass in the pumps, but pulling heavy machine or lifting long boom does.
thanks, makes sense
If the pressure test is done at full throttle the pump will overcome the leakage. That is why I do tests at idle and part throttle to see what’s really happening. The pump should produce nearly full pressure at low rpm.
Usually pump with that amount of external leakage ( to case ) also develops cross port leakage ( from discharge kidney to intake kidney) and not able to build up decent pressure! But I’ve seen series 90 once where the two parts cut the groves in to each other so deep that the pump was able to build half decent pressure!
I would check the passage between case drain filter and tank, as well as tanks pressure before condemning the pumps - the slipper lift noise can be caused by high case drain pressure!
I know the guy who lost $8000 by leaving the rag in hydraulic tank and having deaf ear! Killed freshly rebuild pumps in 40 minutes
I understand checking hose to tank for obstruction, did pull hose and see if had good fluid flow out of tank but did not check hose from filter to tank, explain what you mean when you say ''check tanks pressure''
Check with CAT but as far as I remember the highest in tank pressure allowed will be 14 psi, your vent valve might build up pressure more then that. The no tank pressure is bad because tank sits lower than the pumps inlet and pumps might not get enough oil at higher flow demands and start to cavitate, too high of a tank pressure is bad because it creates restriction for return and case drain. BTW combination of plugged intake and high case pressure creates the “bomb” effect for piston pump! It destroys the pump in the matter of minutes. I’ve seen retaining plates screws with ripped off heads, and retaining plates all bent up and in pieces!
He had replaced his tank vent early on, swapped out with a new one, and confirmed that it held 10 psi iirc. All filters have been replaced and inspected for debris. None found. That was long before rupturing case drain filters though.
Yes, I read that, but like you said - it was before rupturing filters, and the sounds that pump made was like slippers lift, and number one reason for slippers lift is high case pressure.
And he just admitted that he didn’t check passage between filter and tank. The pumps might be ruined, but it’s important to be 100% sure before wasting $6200, and it is important to find what killed the pump in the first place, before ruining another!
I am not an expert but being familiar with machine it acts like one pump is real bad weak , going back to swamp in morning and check case drain line and get dozer over there so can scoot it to dry land and pull pumps monday, any suggestions where to get best pump at good price? Want a quality one not a china cheap-o hate trouble lol
I’m not that exirienced yet, so I sell components! $6200 seems like not bad of the price, if they warranty it, but probably to warranty they would want to install it then selves. You probably not gonna get a new one ( it’s probably obsolete or cost prohibitive). I still didn’t investigate what brand and model that pump is, as far as I remember 320b has A8VO in it. And I never dealt with CAT. So I’ll let CAT owners chime in. In my neck of the woods Flynt Hydrostatic has good ratings among people I talk to.
thanks, cat has in stock, yes has one year warranty, this is a 315CL, will check out their website thanks TVA
Did you cut and inspected the case drain filters, especially the first one? Did you see any debris?
did not have to cut lol. element clean
Usually you should see brass shavings from damaged valve plate and/or slippers! How long did you have this machine?
At least take pump apart ( you think it’s damaged anyway) and post some pictures, may be people here will be able to save you $6000
tenfo
I think you may be missing a trick if you don't go deep into the filter. You won't see the really small particles from the outside, it would need a section cut out of it and squeezed in a vice, then look right into the bottom of the pleats. The video below is of an engine oil filter but it's the same idea.
thanks for good advise
When you dig into the filter that way you may be more than a little surprised at what you find, or not as the case may be.........
tenfo
Excellent advice! This should be SOP for maintenance. If you don't have time to inspect the filter, put it away till you do.
pump video can hit function for split second and not blow filter open, filter is behind pilot pressure filter and not visible in video but can see case return line jumping
You've got a bad rotating assembly. You are sending shrapnel downstream. Don't run any longer than it takes to stow your boom, so you can drag her out. I'm sorry .
will do thanks
I will send you detailed cleaning instructions. Its up to you whether or not to follow it to the letter. It is very expensive compared to the cost of the pump. A lot of oil and filters and labor. Again, I'm very sorry, especially when you were trying so hard to get ahead of it.
understand will have to purge several times to save new pumps, drain tank and flush new filters etc but how do I back flush the valves etc? Will wait and follow your instructions
Will copy what I have and forward on. I don't want to go by memory, I may forget something important. Sometime tomorrow, when I find the documents.
wow been reading, fun days ahead but not stupid enough to put new pumps on and run chance of having to do later on what I need to do now, thanks for the excellent advice, will start pulling cylinders after I pull pumps tomorrow, lord be glad when I get old enough to quit lol
Question to get it to roll do you pull drive motor side or outside hub an pull gear?
Pull outer cover of reduction housing. Pull center shaft and replace cover. Keep in mind, YOU WILL HAVE NO BRAKING EFFORT. Except for gravity pulling the machine down to earth.
Please be careful.
Tenfo gonna drag with dozer
Cat now says 90 days out, me an wife pulled pumps an set in truck, not bad for 68 years old lol, need find new or reman pump somewhere
What about opening them up?
If you were wanting to look, I'd focus my time on the L/S or rear pump as you are facing it. But I will bet a nickel you'll find one piston/slipper completely hammered out with an oversized hole. It pains me to say this, I think your pump failure is a symptom of the problem you originally had. I suspect that the sudden strain on the lazy side was too much for it to handle. A bad rotating assembly would not have caused your original concern. A bad compensator , yes. A damaged main control valve passage, yes. Not a piston assembly. I would wait for others who have more intimate CAT knowledge to share thoughts. Yes your pump is bad, no, I don't believe you're out of the woods yet. I wish I had better news. BTW very brave of you to post your spouse's pic with these degenerates
That’s what worries me! What is a cause of this failure? First check - usual suspects: suction and case drain!
Very nice truck!!!
If you go back and watch the first videos, it looks like the one pump is not stroking up or if it is, it's not doing work until he brings the other function in . He reported that it tracked good. First thing I always check w/ any split system is tracking. Pump pressure was equal on both pumps, albeit high to my experience. I almost never saw 4k pressure unless in boost. Dont know specs, couldn't speak to it. I had a similar situation on one , only one machine. It was a zero swing , equal pump pressure, good cycle times, everything on pump 1 was retarded if operated off only L/S joystick. The moment the R/S was stroked to any function, the pump came alive. I was advised by my help desk to change the main control valve. No reason given despite repeated pleas. Just replace it. That was it, although I do not know what we "fixed" I keep that in the back of my mind, it's hard to throw out when you have no backing or justification.
Not a CAT man, but drives usually governed at about 4600-4700 psi, everything else little lower. Flow regulates by negcon pressure and power shift ( TVC or torque limiter ) when computer sees drop in RPMs. Negcon pressure drops when any of the spools starting to cut the flow in the main gallery.
I had one Kobelco doing the same thing but without the noise, boom wouldn’t come up, but combined operation seemed to helped little bit. The owners request was to know weather pump was bad. So at first I tested the pump, which turned out to be on the tired side ( about 70% efficiency) but pump was able to build up 5000psi. That one was interesting - most of the leakage was crossport, at 5000psi was not even half a GPM at the case drain flowmeter, although flow dropped from 20gpm at stand by to 16gpm at 5000psi. But replacing main relief valve for the section that operated boom and bucket fixed it!
I would like to get some more eyes on this thread to get more ideas and opinions. Not discounting what you've encountered that's very good thought but we need to get to the bottom of this before he puts the new pumps on and has another failure. I'm still wondering if there is something that is occurring when you pull the 2nd function that's allowing the oil to drain off so that the pump can stroke up . I can't figure out from where I'm at what is actually happening is it the pump stroking up or the spool shifting. You really can't tell without having almost everything gauged up at one time Any doesn't even have to hold the 2nd function engaged just touch it then the other pump comes in and stays in that's what makes this so baffling
That’s what I tried OP to do! Put some gauges on control lines to have SOME idea what is going on! But then filters started blowing! It seems like you think that the damage occurred because of over pressurizing, which is possible but highly unlikely! Between port relief, main relief and pumps compensator.
Not so much over pressurizing, more the idea of shock of having the swash plate slammed to Q-max from Q-min. Without a gradual lead in or an accumulator to cushion the swash plate, I could see how that would lead to a failure.
Might be interesting: https://www.eiseverywhere.com/file_uploads/4bba10b4b2e69d0417ccb276948080d3_PistonPumpFailure.pdf
Good read, thanks. We'll wait to see what the guts look like. I still think think there's something in the wood pile waiting to be found
I read another one, Oilgear published it, they were recording pressure pulse of case drain and from that they could determine what condition pump is ( especially pistons and shoes), that’s for industrial 24/7 systems, trying to plan next pump replacement! I can’t find it at the moment, when i do I will share it.
Found it!: http://www.alliedsystems.com/pdf/wagner/forms/80/80-776.pdf
The vary last page is a Gold!
Once again - I’m not a CAT guy, but it seems like someone was messing with releafs on that machine, 900psi is definitely too high, 4900psi on functions is high on machines I dealt with. So it might be combination of things. Like Dave at NorCal. says “multiple offenders deluxe”
Excellent! Great information!!
thanks that is good good stuff, found pump an gonna replace cooler an start cleaning everything
Pulled bottom plug, fine fine shoe brass, but no other metal
Which bottom plug, reservoir or sump pipe?
You really need to take the pump apart and especially examine the barrel faces and port plates. Not all hydraulic system contamination scenarios are the same and before you proceed, I would suggest some critical analysis of what has actually happened.
I will second that! If you worried about putting it back just take pictures as you go! Who knows, you might save a chunk of money!
going to follow everyones advice in morning, will open and take pics pulled plug in bottom of case , right in center flat part,
manf. of the reman pump says use ''30 weight non foaming rust & oxide oil'' your thoughts?
Who is the rebuilder?
Sounds like recommendation for compressor!
Hydrostatic-Transmissions.com out of Mississippi, what do you mean by recommendation for compressor? What oil do you recommend?
A good-quality (not parts store brand in other words) SAE 10W hydraulic for your climate would be my call. What does your Operation & Maintenance Manual say..? (I'm assuming that you have one.)
ISO 10, just wanted you experts to verify, yes have cat ET and SIS on laptop
I’m in Mobile not that long, I heard about another place somewhere in Hattiesburg. Back in Seattle it was HDR in Pyuallup. But I did use small place in Tacoma called Epic industrial Services. HDR is part of Hydraulex, Flynt Hydrostatic is part of Hydraulex also.
Check out this place here on forum! It sounds like the one a lot of members had bad experience with! Suspiciously they had good reviews only with people from Tupelo. I think they sell the service on eBay as rebuild/exchange for Sauer Danfoss Series 20! If that’s the one - stay away from them!!!
https://www.ebay.com/itm/20-2082-Sundstrand-Sauer-Danfoss-Hydrostatic-Hydraulic-Variable-Piston-Pump/381682492736?_trkparms=aid=444000&algo=SOI.DEFAULT&ao=1&asc=20171010182220&meid=585ba33e6ceb497489fd7330cf2dc58b&pid=100891&rk=2&rkt=12&sd=381682492737&itm=381682492736&_trksid=p2349624.c100891.m5206 Looks like it’s them! Your free to check out your self! But I think they are “famous” here on HEF, as the entity who will promise you “mountains of gold” but delivring on that promise - that’s what they have problems with!!!
Why is it that the thought never crosses my mind to search for heavy equipment parts on E-Bay?
IDK Nyge! I remember even in Seattle Case recommendet AW46, which is SAE 15w-20w. And 90 series case used the same Rexroth A8VO as B generation CAT. Here in Mobile - which has pretty much same climate as Florida it’s a toss up between AW46 and AW68, owners of older more tired equipment trying AW68 in summer time.
Maybe because you know better?
Must be. In my business I have to warranty my work so I cant just buy stuff like that from people I don't know. Seems to be a HUGE gamble to me.
No I consider buying used from eBay for vary cheap as “bones” for rebuild! Like few months ago for Italian made 100 ton travel lift. The original Brevini pump was no good anymore and was absolete! And you know how it goes without core to rebuild! It goes up to$13000-$15000. At that time was whole bunch of industrial A4VS on eBay, with DFR controls $3500-$4000, they had a keyed shafts - but we could fixe that with flex plate adapter from Heayes! We were seriously considering it! But than owner of the machine talked to his friend who worked for Huge oil company here in Gulf, and that friend promised a great price on brand new Sauer Danfoss Series 45 , little low on displacement - but you don’t want to be in real hurry handling 3 million dollars Yacht!!!
Not ISO 10 , SAE 10W. They are different viscosity scales The ISO equivalent of SAE 10W is somewhere in the range between ISO 22 and ISO 32 - see attached chart. @TVA - My last two gigs have been in tropical climates, never below 70F even in the "coldest" of what passes for winter nights. We used SAE10W in all Cat hydraulic systems (excavators, dozers, graders, etc) without a problem. IMHO in Florida SAE10W will work just fine.
Funforfuel nailed that one, found plugwire off lol
Thanks Mr. Nige
Yep that’s pretty much consistent with case drain line convulsions!
Got it Nyge! I think best to use OEM recommendations!
What plug wire?
Ohhh, duhhh
What does the rest of the piston and the bore in the barrel look like?
did not pull it all way down, opened sides and looked in,
Gotcha, well this is a big bucket o suck. We still don't know the root cause. I dont believe the pump was the initial problem. If it is, that's wonderful, I just dont see it.
I understand what you all are saying but walk over to my side and look, excavator makes 1,800 a day, plus I love HUGE risk that is why I have yellow iron, cat is 120 days out on pump coming from '''overseas''' which is sanitary word for ''China'', have a pull off that has been bench tested for 3,500 waiting if this one bad, so when you weight it all out I rolled the dice, hero/zero time, I spoke with ole boy and he was real familiar with what pump was on 315cl and had one and sent me pics ,got it out same day and have a tracking number on 350 lbs of something coming on old dominion my way, will crack sides and see if shoes are new b/c you all taught me so much in such a short time, right now have excavator sitting 100 feet out of swamp in not real secure place not making a nickle, so gamble an go lol
funforfuel am I thinking wrong that I need put it together and see if functions perform as they should? Win/lose/draw need machine to run, to run needs pump, so....? Sure do listen too you all and will continue to listen, lord if I made a bad call on this pump thing I promise you I did not lose my virginity
Optimism , love it! Clean everything as well as humanly possible. With the oil out of the system take the pump discharge hoses off and blow back towards pump into a pig mat or clean white cotton. You're looking for shrapnel and powdered metal. If you find any, you'll want to carefully remove the spools from the valve with the bottom end caps off. Flush each bore with brake clean or whatever you choose. You don't want something getting in between a spool and land, bad stuff will happen fast
you talking about the flow out hose for each pump that go to the valve block right?
It's well yes both hoses from the pump going to the case drain should be flushed clean but I was specifically talking about the pump discharge hoses running to your main control valve we have to be sure there is no debris or lodged material in those hoses that could do harm to your main control valve Considering you lost a slipper face you also want to pull the sump pipe off clean and inspect it as well and then unfortunately you're going to have to do the same on the floor of the hydraulic tank where the standpipe is for the sump.
By the way have you verified that you have a direct return to tank from the case drain filter?
ok, your thinking I know what I am doing, I do not, so hyd tank has sump and need pull belly pan and drain sump? tank is empty right now, going back up there friday and start all this, then pull large port on top and clean standpipe?line clear on case drain to tank, question--the pistons compress the oil ''in the case'' is this true? or is the case drain what takes care of leakage from pistons?
No pistons draw oil in, compress it and send it out to do work. Case drain is minimal. It is considered cooling and lubricating oil. As a rule, pump maximum displacement would yield no more than 5% of that volume to case drain. It should more or less trickle, no heavy flow. Some folks actually call it leakage.
The most crucial things for pump is suction and case drain, everything have to be clean and freely flowing! Than overpresurizing issue, if you think you’re up to the task of rechecking and resetting everything, I think we can give you general procedure guide lines, and very experienced CAT mechanics should give you their wisdom ( idk why they are in the shadows right now, except Nige) but I think you gonna need manual for that. What is the efficiency of that used pump? Do you know?
Piston compress oil in the barrel! Think about it as revolver style engine block! Case flow that’s like blow by, but in pumps case most of the time it’s mostly from valve plate which you can think of like cylinder head.
By stand pipe you mean return filter housing? There’s two flange style lids on hydraulic tank, you already met suction strainer lid, the one with vent on top, the other is return filter lid. That’s two biggest holes except one on the bottom to do your cleaning through. Although return filter housing will be more of a hassle !
If the suction hose will be too stiff and not playable, I suggest to cut it and throw away. Same with cooler hoses.
Sorry, I forgot that you already have pumps off!
Some light bathroom reading material
Cont'd
The last of it. Again, it's up to you as to how closely you follow the instructions. It is what is recommended to clean your system to make a safe place for the pump to live and not cause any further damage
Oh boy! That’s a one dirty, sticky slimy job!!!
Sorry, I do not have a printer to convert to pdf or I would have.
Lol like me some pain!!!!! Ole boy told me long time ago ''ya can chop a redwood down with a spoon, ya just gotta want too'' so I think of all this as anti-nursing home medication hahaha
I recently bought my self a plastic caps and plugs kit from New Line, I once I asked my grandpa : why you still work so hard in your age? He said: because if I didn’t - I would get sick and die! He died in his sleep at 93!
yeppers
How are things going for you? I know you're busy, just checking in on you.
Good day This thread gets rather a long story just a thought of experience we had in the past, the howl from the pumps was almost non existing when the suction strainer was removed for diagnostics, eventually the fluid was found to be of the wrong viscosity after testing may be that this has been overlooked. Kind regards Uffex
The simplest thing is often overlooked. I never even considered it
I didn’t read anything about wrong fluid! We discussed some rebuilders recommendation for the rebuild pump! IMO questionable!
What Uffex is trying to explain is that the pumps were howling. He had experienced a situation where the howling stopped when the strainer screen was removed . That perhaps, the wrong oil was in or that the strainer was obstructed. Just another thought to add to the list of potential causes. The more I watch the video , the more it becomes possible. So many possibilities.
Good day I missed to comment at that time Caterpillar had an additive fo the fluid that was very effective to silence the pumps. KR Uffex
Same thing happened when he replaced tank vent - that’s what hinted me to something fishy wis in tank pressure. Every time tank was opened it got better. As far as the remember this “saga”. Well the catastrophe happened, now most important thing to check all things possible so the new pump will live long life.
What exactly that additive did to silence the pumps?
Did I missed something about OP having wrong fluid?
No, no one suggested or mentioned the possibility of the wrong oil. That's why it is being mentioned. Nobody wants to see this man go through all this work to suffer a repeat failure. Just another pair of eyes casting a point of view. What makes this site far and away better than any other. The more possibilities examined and ruled out, the closer he can get to the actual solution.
I just wanted to make sure I didn’t miss anything
Was it fluid too thick and didn’t really pass through strainer good enough?
You know you might be up to something here! I remember Rexroth had a problem with 10Vs, those were moving swash plate too fast and in result were cavitating because the suction gallery was not able to meet the demand of the pump for a while! The solution was to install the orifice between LS spool and upstroke side f the servo piston to slow it down. But there’s two different conditions: 1) as far as I remember it was in industrial setting and suction line was rather long 2) it only cavitated for few moments until suction was able to caught up with demand. The regulator on that pump might have something like that orifice and something might happen to it. Another problem that we ( or I at least) still don’t know anything about that pump. I even sent a picture of it to my friend in Portugal who was rebuilding pumps and motors for many years, and he said that he never seen anything like this, and I know that he is really good about it! He actually identified brand and model of the pump out of obstructed image of it from the parts book, and that wasn’t a picture - it was as only kinda countours of the shape of the pump. The CAT guys might not even know th brand and model of it as to them it’s probably just a part number or the whole cluster of the part numbers.
Afternoon too all, whew weeeee..... been having fun, tank clean, lines cleaned, new cooler, install new pump {another whole story} got it on lowboy and off here at house/shop, going replace all fluid and filters again in morning, gawd sure glad be outta the swamp, wife threatening to quit lol, get fluid swapped out will start checking it all out, now for pump story, pump arrived with krylon rebuild in crate, you all were sure right, guy has awful feedback everywhere you look, i may have lucked out here though said he bought the pump in a surplus package from another rebuilder who went out of business---[hold on gets worse lol]--- tell everyone on this site the guy at Hydostatic-Transmissions.com is one big lie, from beginning to end, anyway won't know about pump till I run it some, but rather have it rebuilt by some unknown than the guy at HTS, filed a BBB report on him and that is when he told me he misrepresented the pump as HTS rebuild, he bit off more than he can chew this time as I will take it upon myself to see what i and my attorney can do thru his state Attorney General to put stop to this shyster, I enjoy this kind of thing, it is like helping people BEFORE they run into trouble, like chopping head off snake before he bites anyone else, anyway, going in morning get brand name barrel fluid and drain and fill and check pressures, so far now howl anyway,
I am so glad to hear things are working out, even though you're in another battle now. Fingers crossed that your replacement pump hangs in there for you.
I told you! I actually talked to that guy on the phone - in first minute of our conversation I knew he was a spinster, and know very little about stuff he is pushing. I have a suspicion that these pumps rebuild overseas, and who knows what quality are parts used to rebuild those! But then again it’s unknown weather CAT not pushing same pump rebuild at the same place but twice the price! Hope everything works out good for you!!! I would really suggest recheck all the pressure settings, because it’s sound like someone been messing with those! Keep us posted and boy would I like to get a hold of your old pump to do some “Sherlock Holmes” work on it!!!
Haha , I had that coming TVA, was needing get hoe out of where it was, yes cat told me they would have to get one from ''overseas'', I have old pump here still will see what ole boy says in morning, lord I will ruin him on internet if he does not play right, his call makes me no difference, will swap out new oil for newer oil in morning and let you know results,
new oil and new filters this morning, no pump noise, have not had time get oil hot and work machine other than in yard, have a HUGE surprise for Andy Soper @ Hydrostatic transmissions will share with you later today. They misuse the internet to stick it to people now they will see what internet can do to rectify that,
Looks like yer out to get your "pound o flesh" Good for you. So glad to hear you're trouble free so far. Fingers crossed for you.
I actually dreaming about building my self a pump and motor rebuild shop. Already have the place for it, even some equipment, but still a loooong way to it!!!
welll ole Andy called and we had a little chat, getting 3,500 back, and then will send him the core, oh yea then I will pull the publicity down, seems he is not fond of it,
To make sure your replacement pump has the best chance of survival depends on "clean" oil, not just oil that looks clean. It's particles you can't see that will kill the pump. A suggestion. Pull a sample of oil from the hydraulic system and have it analyzed for "ISO Cleanliness Code" if nothing else. Your local Cat dealer can supply a kit for the sample included in the cost of the analysis. Other options may be available in your location. Here's a link to an article explaining what the Code is and how to interpret it. https://www.machinerylubrication.com/Read/28979/iso-cleanliness-code You may find that the analysis for cleanliness is included in a standard oil analysis but often it is not, so make sure before you commit. You are looking for an ISO Code of 18/15 or better. Then in a month or so pull another sample and have it analyzed the same way. The Code should be improving (i.e. the ISO numbers are reducing), especially if you throw a couple of filter changes in there as well. It's a shame there are no High Efficiency filters available for your particular machine or I would have recommended that you use those as well.
thanks Nige will call my Cat dealer and get this rolling
Did he admit that was used but not rebuild pump?
Expect a full analysis to cost somewhere in the $40-50 range. Cheap when you consider how much $$ you have invested in the machine.
think the 3,500 was the confession
ok, here goes, pump closest to counterweight i will call rear pump pump closest to bucket will call front here test results rear pump at idle 1000lbs wide open throttle 1000lbs full throttle results are boom up to stops 4200 lbs boom down ground an hold 3200lbs bucket curl in/out against stops 3800lbs front pump idle 900lbs full throttle 900lbs stick out 4400lbs stick in 4200lbs boom up 4200lbs boom down 900lbs hold boom down lever full open and hit stick out pressure goes to 3000lbs pump goes up to 4500 and can tell opening relief as it should but should hold around 4500 not drop off to below 4k, goes boom up against stops and holds around 4200 when lifting bucket full can tell now right, slow and no power, curl seems ok, stick in/out seems ok. boom against ground bad
like before, bucket against ground barley lift machine, used to shoot in air, hit stick out function with boom down function held wide open it shoots unit into air,
Boom down pressure too low IMO, need to check port relief, try to swap it with boom up and see if problem will follow!
But first check with manual what is your stand by ( idle ) pressure supposed to be! And don’t run machine until you fix that.
where is it located?
You mean boom down relief? Main control valve, look to your manual.
I think I can find a book somewhere and get back to you in awhile. I seem to remember that NC pressure should be around 300PSI with everything in neutral.
what is NC pressure?
Negcon that’s the one you have at 900 and 1000 idle. It should only drop from there!
It's negative control pressure. It is minimum flow from the pump when nothing is being used.
Start with pilot pressure at filter and what is supplied to each valve when at full joystick travel.
ok been reading about negative flow on boom cylinders, ok so hook gauge to pilot pressure and open each function full and read pressure or open to full stop and check pressure?
If your checking pilot pressure, go to full stroke in each direction on the joystick. That will tell you if the pilot pressure is consistent throughout each flow direction. It will not tell you how much travel is happening in your main spools.
will do it first thing in morning and report back
I would suggest to take care of too high of a stand by/NC pressure first, before you do anything else! That’s the one that works with your pumps controller! I have suspicion that’s what killed previous pump!
do not have a clue how to do what you just said TVA,
The CAT guys gonna have to help you with that!
what regulates the minimum flow when in standby? This pump came with pilot pump on it so will check see if it is putting out 590lbs, other pilot pump was 900lbs and I adjusted it down at filter housing, this one may be weak and not spooling pump all way? will keep gathering info till one day get it fixed or be ready for nursing home lol
The unlloaders ( it will have different name like “open center low pressure relief” or something like that), stand by idk on your pump, K3V has mechanical minimum swash angle plate, A8V I think was hydraulicly. Got to look in to manual!
Just finished working, was a wet one today! So here it comes: tot pumps flow controls by NC pressure, that’s what you need stand by for! Control Avis an open center but at the end of main gallery is unloader which creates a restriction to generate a stand by pressure. Different pumps provide stand by flow in different manner but it’s have to be there in negcon flow control system. Negative Flow control means: the more pressure you have in those control lines the less flow you get from the pump! At neutral your center gallery is open and you have full specified negcon pressure and because of this you have minimal flow from the pump ( stand by condition), when you move at least one soool in that control valve you cutting flow to the end of gallery, you NC pressure drops and pump increases the flow!
The machines I work with both pilot and NC is 400-500 psi. That’s usually Kawasaki pump and Kawasaki control valve!
Here is what NC or negative control pressure is and isn't. It is not pilot pressure. Pilot pressure is flow from a gear pump mounted on the drive for the main pumps and it runs the control system of the machine. Pilot pressure relief spec is 595 PSI plus or minus 29 PSI. It is set on a pressure regulator valve. Negative control pressure is created when oil from the main pumps enters the main control valves and travels down the center of the block with all the spools in the neutral position until it gets to the last valve section. At that point it dead heads and there is a small orifice that connects to a hose which runs back to the pumps and connects to a spool in the pump that controls oil going to a servo piston in the pump. Next to that orifice in the main control valve is a relief valve cartridge that when open allows oil to go back to the hydraulic reservoir. The cartridge valve holds a set pressure through out the main control valve center. In most other manufacturer's systems that pressure is around 300 PSI. Caterpillar does not give a specification for it. At any case 1,000 PSI does not make sense for a NC pressure reading with the valves all in neutral. When a valve spool is moved it sends oil out to a function and takes it away from the center section of the valve which drops pressure on the NC circuit which allows the pump to stroke up. I would suggest that the orifices might be plugged, the NC relief valve cartridges in the main control valves have problems or someone has messed with the minimum flow screws on the pumps. The way to check this is to Tee into the NC hoses where they connect to the pumps and watch the pressures move up and down when something is operated. When you pickup of the boom the NC pressure should drop. When you stop operating all the controls the NC pressure should rise. Hopefully someone will come along and provide a pressure spec so you could know if that part of the system is operating correctly.
Just to clarify: I didn’t say that pilot and NC pressures had something to do with each other - just happens to be the same value. Should have been more clear! I apologize! I think the fact that his NC is too high but remains constant across all range owners RPMs points out not to plugging issues in drain side of the unloaders but to settings been messed with. With plugged drain he wouldn’t have good flow at all, or at least pump would bee super sluggish. And NC pressure would rise on increased RPMs.
Great explanation, I have had the machine for over a year with no issues, no one works on it but me, not possible anyone has been messing with pressures to my knowledge, do not know if this caused any of my trouble but I made a large palmentto rake to fit on bucket, it is heavy , could I have overloaded the system? I can tee into lines at pump if you tell me which ones to get readings from, again great explanation thank you
If I’m not mistaken NC reliefs not screw adjustable but shim a One more thing to know: you have relief valve on each function and on each side of it. For example boom up has its relief and boom down has its own relief, and so on, and so on! Then main control valve divided in to two sections one for each pump and joystick; let’s say your rear pump controlls buy left joystick and goes through section A, and your front pump controls by right joystick and goes through section B if main control valve. Each section also had its own main relief valve. The setting go something like this: ( let’s say Kobelco settings): mains is around 4900, travel is around 4700 functions is around 4200-4300. There’s only two hoses (lines ) between section of control valve and corresponding pump: small (1/4”) is NC control line - that’s the one you want to tap in to! And big ( probably 3/4”) that’s your main supply. There’s also combined operations between pumps and sections but that for later! Looks like nobody has information from CAT ( just yet) what NC pressure should be, but there’s consensus that it unusual to be that high! Another thing is I don’t like your boom down pressure ( seems about 1000psi too low ) that might be relief cartridge problem. And something looking fishy with combined boom/stick operations but that one needs to be verified, and let’s stick to single operation for now. I think after you sort out your NC question you should find and swap your boom port reliefs, and see if the problem will follow the valve.
The theory (or suspicion ) about too high of a NC pressure killing your pumps doesn’t say it will do it right away! It might take longer time. I don’t think we have an engeneer on this thread who can tell us more certain, but techs who are here consider this suspicious and potentially dangerous. Until proven otherwise.
Floridamechanic? Why in the hell your up so early?!
Because I want to be awake before I die, and you were right ''something fishy'' comment early on is showing itself
You mean few pages earlier? That’s OK, you’ll sort it out!
yes sir, now I want to know what every line does,
Service/repai/shop manual is a good thing for that! BTW not all excavators have NC flow control, some of them Delta P. But that’s beside the issues you have right now.
Not sure about cat machine but kobelcos have one main relief valve which does both pumps and each function has its own port relief valve. Port relief valves should always be set to a higher pressure than the main relief other wise the main relief valve will never need to open cos the port relief would of already drained away the pressure.
I haven’t worked on newer machines but on older every section has its own main relief! Can you answer the question? When did they switched from JIS Kobelco to DIN fittings?
OK! Our Irish friend was right about main relief! You supposed to tighten main relief 180 degrees, check and readjust all the port reliefs then return main relief back! He was wrong ( at least about the “girls I go out with”) about main relieves: there’s MR1 in block B, and MR2 in block A: Following information just an example, out of first manual I got my hands on this morning: Main relief: for attachments - 4270 for travel - 4690 Port relief: boom - 4760 Arm - 4760 Bucket - 4760 Swing - 3130 All this information varies from machine to machine, and I think I’ve even seen difference in port reliefs settings for the same function, I don’t have time to look through all of my manuals But you get the idea!!!
New pump I just put on, numbered lines so will know what you guys are talking about, tested pilot pressure both sides filter housing, 600lbs and holds thru all attachment cycling, number 6 test port shows 200lbs, have no clue what it does but has test port so I figured may help.
Driving right now, can’t look at the picture, number 6 might be your EPPRV feed to regulators, does it comes from solenoid with adjustment? If you have no noticeable drop in pilot pressure upon actuation of ALL functions, then probably all you actuators are OK.
Any noticeable difference in track operations?
no sir, tracks fine, good and strong and straight, that #6 line pigtails off pump with test port. two other lines come off same port, #7 goes to filter housing as pic shows and #8 goes over to main valve
Do you have manual for this machine?
( at least about the “girls I go out with”) Lol just for my own knowledge what kinda girls do you go out with. I have worked for kobelco since 1999 and never seen one with two main reliefs
OK I’m not gonna argue at this time, what about fittings question?
If you look by the #5 marker there are two hoses. One appears to turn off and go into the bottom of the pump on the right side and the other to the pump on the left side. I don't know for sure but I think those are the NC hoses. It's difficult when I can't put my hands on something and trace the lines out. Those two lines should go over to each end of the main control valve. They should hook to a fitting that can be removed which has the orifice in it.
I am not trying to start an argument with you I am just asking a question. As for the fitting we get a bit of everything over here but mainly jis on older and din on newer
Yes, I know that, just no one can answer me when the hell they switched ?
About arguments - I’ll check diagrams, and come back to you!
ok , when I get back this afternoon will trace where they go and if they go where you think will pull and see, you think orfice may be plugged ?
I'm not sure but it is something to eliminate as a cause that hasn't been checked before.
You just stole the words from me! I find it hard to believe that someone will go to the trouble of re shimming those unloaders ( I’m not even sure they are shim adjustable)!
OK boys! Drive is over! Now it’s worky time! I’ll read you tonight!!!
goes to this apparatus what ever it is the most forward line in pic
That looks like the solenoid stack for things like two speed travel, swing brake and such. So that's where those two hoses connecting to the main hydraulic pumps go to? I don't recognize that from my memories.
told you wrong 6 is test port 7 to swing motor 8 to that solenoid block you told me trace 4 and 5 they both go to side main valve block where pointing in pics --look like attached too fitting?
looking down on main valve body hoses come in on left side
If you look at the main valve body at the bottom in the middle of the casting you will see a hose with a 90 degree fitting on the end attached to the valve body. That is the hose that should go to the pump for NC pressure. There should be another hose on the other end of the valve that goes to the other pump.
there a a lot of hoses coming out bottom of valve but only two that go direct to pump are two large feed hoses at top of pumps and two smaller hoses that go into side of valve body in pic #4 an #5 in pic, they each come out of what I call actuator arm, pulled it off old pump and has ball socket for spooling up pump I guess, those two lines are ones i am pointing to in pic, on each side of pump is manual adjusted pressure regulators that assembly is held on by 4 bolts, i pulled the four bolts on old pump that is how found slipper shoe fragments, this is where ball socket is located to spool pump this is where each side has a line coming out going to main valve in pic----just looked and cat calls that pump actuator where hoses is located on each side
Those are the lines you need to tee into and read the pressures at high idle neutral and at high idle something like boom up used.
ok will get that done and post results, what should they read? Both sides same?
That's the pressure that we don't know. They should be somewhere below 1,000 PSI at high idle everything in neutral and they should drop when you operate something. So when you pick up the boom both should drop down at the same time and by similar pressure readings. The farther you move the joy stick handle the farther down the pressure should go. If the system is working properly the lower that pressure drops the more the pumps will put out.
I guess you thought you will just keep working on engines and that’s it?! But turns out life and us here - will make you become excavator Tech also!!!
Kobelco Ireland Would you please find: book code no. S5 130739E And go to page 9,10 there’s diagram there, (for the valve KMX13C/23011) and tell me how many relief valves item 601, also having designations MR1 and MR2 (KRM15EK12) for each block A and B? I will grant it to you that on illustration ( page 1,2) designations for MR1 and MR2 is missing, and show MR1 only and it called “MAIN RELIEF VALVE” but both MRs showing on Control Valve diagram. But if you find book code no. S5LP0407E and go to page 8 you can see both of them designated, and MR2 is to the bottom and left from arm actuator.
Actually you can find MR2 on the bottom of the A Block!
Glad I can entertain you while learning to be excavator tech hahahaha, will have to get two pigtails made at hyd shop so can watch pressures, will let ya'all know results today or tomorrow
John can correct me if I’m wrong, but I think you gonna need 1/4 ORFS swivel run tee, gauge 0-1500 ( with your current settings, usually it’s 0-700, or even 0-600 for these things ), and a hose to connect to gauge.
If you wanna to have good pressure reading kit for a future use, nicer ones with micro bores 16x20 test20 or mini mess, go to EBay and type in search “hydraulic test” and there’s boat load of them various prices and combinations. They are OK for the equipment owner occasional use. I had to build mine from scratch, with genuine German more expensive stuff, before all these Chinese knock offs showed up on eBay. I have many microbores different lengths, for these I tee in to both lines, put my microbores through cab window, sit inside, watch the pressures and write them down.
will go look thank you sir---yep you are correct the ORFS fitting is exactly what will need, did not even know they existed, went to ebay and looked too, have Stauff gauge set now and have used it for years but I see I have a junior starter set lol
Well good luck to you! All the best!!!
I am out in service van and won't be back in workshop till Saturday so have no access to books till then. What model and year machine are we talking about I am not trying to prove you wrong on this I am just interested for my own knowledge cos its something I have not come across
…………………..and this is why you shouldn't throw someone under the bus before all the facts are in.
?
not for you
OK
Good day guys I have read this thread several times so I hope I did not mess up, I have made notes and drawn the following conclusion from what has been posted. The pump howl was the original issue and I suspect this has not been resolved, the illustrating video if I have followed correctly does not indicate a significant problem. I have posted my notes without so that you may see where my conclusion has come from. First post Pump howls when the ram is powered outwards away from the machine. Post Jan 17 Tank pressure is 2 lbs this will only max out when you fully stroke the cylinders a couple of times. Post Jan 18 Nige Suction strainer condition important Funwithfuel check if you have a pump issue flow test again a very important question John C comment very low hours Indeed very low for a pump failure Report that both pumps are making 4900 p.s.i (345 bars) enough to work the machine. Question when did this howl develop? Are you aware that the cylinder force for arm out is considerably less than that for arm in.? Jan 19 Funwithfuel is focused on pump flow you do not appear to have made the crawler speed check he requested, you have only stated that the dealer had given a green light but the dealer did not fix it. I suggest you check it and confirm if it meets specifications. In the video you appear to be operating the arm out in unison with the boom down and raising the undercarriage, when you do this you are not only using the boom cylinders negative chamber which may I point out is the weak side of the cylinders,lifting power will increase when you operate the arm as you have added an additional cylinder to support the weak side of the boom cylinders. If i have followed your actions correctly this is a normal reaction from most excavators. Pilot pressure is that 900 p.s.i. 63bars that seems high to me 595 I believe is normal. Adjust to the correct level on Jan 20. Feb 1 Case drain filter burst indicates excessive case drain flow TVA good advice check out the pumps first. Comments that the pumps make high pressure conflicts with excessive case drain Pumps failing at the hours on the machine would be considered as apremature failure has the hydraulic fluid been tested for visco what is the condition of the suction screen filter? Feb 2 TVA comment back to the suction system !!correct what has caused the pump to fail if it has ??? Take the pump apar t good advice Feb 5 Cmark take the pump apart good advice try to establish root cause. Nige check the fluid good advice seems to go unheeded
Could not stand it went to big city got fittings, test results all at full throttle call pump closest to counterweight pump #1 Call pump closest to bucket pump #2 Started unit and at full throttle pump #2 had 2k lbs, hit boom up an pressure drop to 1000lbs at boom up max, no pump noise and pump #1 had 900lbs, as boom went up it dropped ending at zero with full boom up, So i shut it off and recorded results, restarted now pump @2 has right at 1000lbs and drops to 500lbs at full up, push boom down at half throttle unit goes up in air like old times,but when I do stick in/out or boom up/down i get slight slipper shoes sound just for split second, and real light, but pump #2 will not drop to zero like pump one, curl bucket in or out at stops gauge is zero and lugs motor, now will lug motor boom up/down--stick in/out, so do I have trash in valve or valve sticking? hooking gauges up at valve block not at pumps, have to go get on dozer before lose this job be back this evening
When you come back, start the machine, let it warm up, put it in normal digging mode ( if it works) or high idle ( let’s say half of available RPMs or a little lower if your modes don’t work ) and run tests again. Don’t do combined operations, at this point dead heading something is not that important as have joystick all the way in full position. I don’t know your pattern, but let’s say yor right joystick operates boom and bucket, operate the longest cycling one and watch the pumps NC pressures, one of them should drop pressure considerably - read and record that one! Then switch to the other.
Nige! Can you please repost that diagram?! It came out too grainy on my end and I cannot read it!?
both normal digging and high idle, just did that and came in and read your request, unit warmed up both nc show 900lbs, all functions are a LOT stronger since putting test fittings on, for some reason, boom full up both go to zero try kill engine boom down #2 pump drops from 900 to 450 an stays at that no lower, pump #1 stays at 900 stick out both pumps drop to zero and load motor hard stick in both drop to zero and load engine hard curl in and out both drop to zero and load engine hard getting chirp chirp thru all functions boom down 10 times stronger than when first started and pump #2 was at 2k at high idle in neutral then all sudden has fallen to 900 and a lot more power but still not dropping to zero in boom down oh yea I still have old pump lol
Let’s wait for the rest of the council to chime in! But I agree with John and I think what you just said hints more that way - that you having NC drain and unloaders sticking issues! Do you think you can find those orifices by Johns directions? I take your 2000psi was on cold oil? Another question are al the return lines from control valve to tank clear. Again feels like drainage issue.
TVA I ain't got a return line clue? lol, yes can/will follow directions if ya'all can do' 'run spot run'' directions, by now ya'all know I ain't the sharpest knife in the drawer-- yes was on cold oil
I think it’s something that needs to be crossed off the list before proceeding farther. Just MO!
Driving, read it again. So NC doesn’t drop only on boom down? What grade is a new oil?
So, your boom down is on the right joystick? Right?
if some are thinking it is a case drain (or return line back pressure issue), it could be a failed hydraulic line on the inside of the hose, making a restriction. (I am new to excavators, but have worked on farm machinery with hydraulics for a long time, and have had failed hoses on the insides more than once.). Just an outside the box thing I thought i’d offer....
correct boom an bucket curl right stick ==10wt yes it drops from 900 to 450 on #2 pump I think if would drop lower then other pump would kick in but not sure, was crazy b/c went from 2k in neutral to 900 in neutral in a 60 second shutdown/restart, and has remained there
Now we are getting some results that can be interpreted. Part of what is happening is that you have combined flows from both pumps depending on situations. Run the test again this time using only the tracks. Pick up one track and slowly start it spinning. The associated gauge should slowly drop as you add speed. When it is full speed the gauge for that pump should read zero or near it. Then do the same test on the other track.
thanks jonno we are taking all offers lol ok will be back few minutes
Yeah I saw that both pumps spooked up on boom up and stick operations, but I’m not familiar with CAts I’s and II’s!
I was thinking about return restriction too , but let’s just be methodical, one step at the time! This way will be clearer what’s going on.
ok, swing over an lift either track and engauge both sides drop to zero on each pump, crazy part is now at idle it with boom forward it shoots unit in air better than ever has and has way more tracking response power at idle than it ever has, kinda cramped quarters for night time travel sure neighbors will have questions
Too high of a NC pressure can cause a lot of bypassing in regulators and overheat the oil! Possible reason for dropping from 2000 to 900. There’s also return filter bypass to consider.
Can you see your oil temperature?
yes not hot at all, can run a/c and dig hard and will stay normal, i keep all coolers/radiators pressure washed
Air Is your boom down drops NC to zero now?
Air purge? Maybe?
If engine is lugging too much you should also do a prv calibration (power shift pressure)The prv solenoid comes with the pump and should be recalibrated after pump change. You can do it through monitor in service mode. Password is usually f f f 2 to enter service mode.
I have to go! I would suggest leaving gauges in place and record pressures on cold oil tomorrow morning! Good night!
took prv out of my pump and put in this pump, do have cat ET but prolly not smart enough to do calibrate without coach, night TVA, dozer till afternoon tomorrow-- thanks mobiltech
yea gotta go for tonight, 4am comes early will get in tomorrow afternoon and see what it does cold then hot, thanks to everyone
will walk machine and warm unit up and post results late this afternoon, may give more clues
Good luck!
Can't remember if I posted this before (I don't think so but I have slept numerous times since this thread started) but here is the Hydraulic Schematic.
Wow!!! There’s a world of difference! This time it is even in colors!!! Thanks Nige, I’m not familiar with CATs I’s and II’s, this will help!
During a BOOM LOWER operation, the oil delivery from only right pump (23) is supplied to boom cylinders (1) through boom I control valve (9). Boom I control valve (7) operates alone. Boom II control valve (18) has a regeneration circuit that functions during the BOOM LOWER operation. This function supplies return oil from the head end of boom cylinders (1) to the rod end of the boom cylinders. When the joystick for the boom is moved to the BOOM LOWER position, pilot oil from pilot control valve (20) flows through pilot line (22). The pilot oil flow then divides into three flow paths. Part of the pilot oil flows through port (5) to boom I control valve (9). Part of the pilot oil flows through port (21) to boom II control valve (18). The remainder of the pilot oil flows through port (7) through boom drift reduction valve (12) and the oil acts on spool (17) . The pilot oil flow from port (5) shifts stem (27) in boom I control valve (9) against the force of spring (28) and spring (30). The oil delivery from the left pump in parallel feeder passage (16) flows through load check valve (15), passage (38) and port (6). The oil delivery from the left pump then flows through line (2) to the rod end of boom cylinders (1) The return oil from the head end of boom cylinders (1) flows through line (3) into boom drift reduction valve (12). Since valve (17) is shifted by the pilot pressure from pilot line (8), passage (26) is open to drain port (8). The oil pressure that is acting on valve (12) becomes lower than the pressure in line (3). Valve (12) is shifted to the left and the valve allows the oil in line (3) to flow through line (11). Then, the oil flows through passage (32) and return passage (14) to the hydraulic tank. Since the return oil is restricted at passage (32), the movement of the boom cylinders is slowed and the boom can lower at an appropriate speed in accordance to the flow rate of the right pump oil. Pilot oil from pilot line (22) flows through port (20) of boom II control valve and the pilot oil forces stem (34) against spring (29) and spring (31). Now, part of the return oil from the head end of the boom cylinders enters boom II control valve (18) and the oil flows through passage (35) to check valve (19). The check valve opens and the oil flows through passage (39) through port (6) to the rod end of the boom cylinders. When the joystick for the boom is partially moved to the BOOM LOWER position, stem (27) and stem (34) are shifted upward slightly. Passage (37) and passage (40) are partially opened and passage (32) is closed. Return oil in center bypass passage (10) flows through partially opened passage (37) to center bypass passage (13). When passage (37) is opened enough, an optimum amount of oil flows through center bypass passage (13). Now, negative flow control pressure destrokes the pump for proper cylinder operation. Nige posted all this, I guess none of us read that far down. Let's focus on servo vs pump in regards to right hand pump or r/h pump. It states that servo splits into 3 places. Plus side oil transfers to negative side through boom drift reduction, if that passage hangs open , it's a path to tank. I still believe the problem lies in the boom down circuit . If the path is open to tank, there will be no/low pressure. I believe that bringing the other function helps close the passageway. When your pump is at full stroke and you suddenly close the passage, it shocks the pump, that could also be why you can hear "shoe lift" insufficient back pressure on pressure side of pump Whatever you do, please avoid hitting additional functions while boom down. We dont want to fail another pump.
Sorry funwithfuel! Gonna have to analyze everything you said later tonight! Just super busy today! At least I have VERY beautiful diagram from NIge now!!! ( I must be a dork, beside being an *******, to call diagram “beautiful”)!!!
Steve Ahlgren's thread was 61 pages...………….lets shoot for a new record.
Agreed……..and its been said several times.
We may be dealing with “multiple offenders” here! OP said that he had some fluid overheating issues, couldn’t use a/c and had to slow down in summer. That could have degraded the oil, and degradation of oil led to slippers saying “ screw it, we not gonna take it anymore!”
The statement that NC pressure went to zero when each track was activated tells me the system is now working correctly. Could you tell us the NC pressure with all controls at neutral. My thought is that when hooking up the gauges, perhaps a piece of debris was dislodged and fell out of the fittings. The way the system works is that as pressure falls on those circuits the pumps stroke up. In the boom down scenario if pressure didn't fall the pump would not be fully stroked meaning there would not be enough oil to push the boom down and make up for any leakages or partially open relief valves to enable lifting of the machine. The way to check that is to observe the NC pressure while pushing down on the boom. The NC pressure should drop to near zero for the pump that supplies boom down.
afternoon, ok it is 80 degrees here so difference hot/cold on oil is minimal boom up pump drops to zero quick, boom down goes from 850 to 450 but do have power to raise machine even at half throttle, tracking power is huge increase from ever before, will not track straight the right track is stronger causing drift to left, not major but noticeable[this same pump for boom down}, never been this way before, but when tracking both pumps go to zero quickly, pump idle or high idle pressures stay same pump#1 is 650lbs pump #2 is 900lbs, funforfuel is right in single function very seldom slipper noise, multifunction get a lot more, so boom down not dropping ALL nc pressure, because set to high to handle that much pressure??? dropping 4-5 hundred pounds, which is about half of what is carrying, ya'all already know I sure do not know about his stuff but how about If I pull the nc lines and drain into clean glass jars see any debris?
Does your pilot pressure drops on boom down?
If it was me next thing I would be checking boom down actuator and pilot hoses to it.
Remember boom down by design does not require as much effort or flow because gravity is working with it the only time pressure comes into play is when you hit ground and your trying to break Through the soil
boom goes down excellent an very strong compared to other day, swing over side and boom down shoots in air with authority at idle, it is slipper noise that scares the bjeeezzz outta me
Draining the hoses is a good thing to do to eliminate a potential source of the problem. I would also check the fittings on both the pump and the valve to make sure they are clean also. So the pump that handles boom down is at 900 PSI for NC pressure all valves in neutral. So which pump feeds the right side track? The one with the high NC pressure in neutral or the one with the lower NC pressure in neutral? Pilot pressure has nothing to do with this problem.
Pilot pressure moves the spool which supposed to cut the flow in central passage, just wanted to make sure that actuator is not leaking.
boom down and strong right track same pump= one with strong nc pressure---will pull lines and fitting and blow out and check in morning
It sounds like you have a restricted regulator Drain port. Or maybe a flapper in the hose. Those are a pain to diagnose
As far as we know the only function that doesn’t drop NC pressure is boom down, and it shares drain orifice, unloader, and pump with boom up, both bucket functions and right travel. What it doesn’t share with mentioned above? Joystick spool, pilot hose, actuator and 1/3 of the main spool. I’m gonna be laying down possibilities and you can add to it: Leaking joystick spool Restricted hose Leaking or somehow not fully functioning actuator Debris on the other side of the main actuator Scratched up and leaking spool and/or bore for boom down.
Go back and separate joystick/servo from neg control. Have we established that the servo oil to boom A port is equal to servo at boom B port? For example if you have 550 psi pushing spool @ A side, when requested, do you see 550 at other side when opposite function is demanded? By the same token , is the neg control drop off equal when spool is shifted from neutral to A and neutral to B? This is a lot of measuring, but I think is necessary.
Let us know how things work after you clean out the lines and NC valves. The high NC pressure on pump #2 is possibly caused by misadjusted pump control. If the NC valves on the main control valve are good then the minimum flow regulator on the pump needs to be adjusted. The same may be true for the maximum flow adjustment on the same pump and be the reason the right side is a little more powerful. As I recall in this thread this is a used pump?
Negative flow can be adjusted on each pump. A high setting on negative flow screw in pump will affect tracking. It will also increase nfc pressure signal. You will need to adjust the pump.
Testing and Adjusting 315C Excavator Hydraulic System Media Number -RENR5519-08 Publication Date -01/06/2007 Date Updated -20/06/2007 i01463605 Pump Control (Negative Flow) - Adjust SMCS - 3222-025-FW View Image Illustration 1 g00764907 Pump regulator (right pump) (1) Bolt (2) Cover (3) Seal (4) Spring seat (5) Spring (6) Shim Perform the following steps in order to adjust the right pump. Remove two bolts (1). Remove cover (2) and seal (3). Remove spring seat (4) and spring (5). Add shims (6) in order to increase the negative flow. Remove shims (6) in order to decrease the negative flow. Refer to Table 1 for available shims and shim thickness. Note: A change of 0.1 mm (0.0039 inch)in shim thickness will change the negative flow rate 2 L/min (0.5 US gpm)at a negative flow control pressure of2350 kPa (340 psi). Table 1 Available Shims Part Number Shim Thickness 099-3669 Shim 1.00 mm (0.0394 inch) 099-6109 Shim 1.05 mm (0.0413 inch) 099-6110 Shim 1.10 mm (0.0433 inch) 099-6111 Shim 1.15 mm (0.0453 inch) 099-6112 Shim 1.20 mm (0.0472 inch) 099-6113 Shim 1.25 mm (0.0492 inch) 099-6115 Shim 1.30 mm (0.0512 inch) 099-6117 Shim 1.35 mm (0.0531 inch) 099-6118 Shim 1.40 mm (0.0551 inch) 099-6119 Shim 1.45 mm (0.0571 inch) 099-6120 Shim 1.50 mm (0.0591 inch) 099-6121 Shim 1.55 mm (0.0610 inch) 099-6122 Shim 1.60 mm (0.0630 inch) 099-6123 Shim 1.65 mm (0.0650 inch) 099-6124 Shim 1.70 mm (0.0669 inch) 099-6125 Shim 1.75 mm (0.0689 inch) 099-6126 Shim 1.80 mm (0.0709 inch) 099-6127 Shim 1.85 mm (0.0728 inch) 099-6128 Shim 1.90 mm (0.0748 inch) 099-3670 Shim 1.95 mm (0.0768 inch) Install shims (6) in the pump regulator. Install spring (5). Install spring seat (4). Install cover (2) and seal (3). Note: Inspect seal (3). If the seal is damaged, replace the damaged seal with a new seal. Install bolts (1). Tighten bolts (1) to a torque of 95 ± 15 N·m (70 ± 11 lb ft). Adjust the left pump in the same manner as the right pump.
That’s not a negative PRESSURE adjustment, that’s a minimal stand by FLOW adjustment, it’s even stated in that instruction. The negative pressure regulated by NC relief valves in control valves, and if NC pressure stays the same through all range of RPMs then those reliefs work correctly ( but miss adjusted) and there’s no restriction in the drains. And you right about miss tracking if the NC is different between the pumps at the same RPMs than track motors will be getting different flow at the same RPMs. But this statement only true for partially open pilot valves, or if at fully open pilot valves theres still a NC pressure on one or both sides.
And we FINALLY we have the right value for NC pressure which sounds about right - 340 psi!!! That’s a far cry from 900-1000 psi. Thanks!!! Mobiltech!
ok going to clean out lines today, the nc lines go into side of block, where are the valves?? my plan was to pull lines and use siphon gun with diesel to blow out and check flow,just reread post, so if I pull control valve for boom up and boom down and their reliefs clean all them and blow out passages then test, the nc valve is in the control valve, will do this today and report back, have to put new idler on my dozer first, new ITR undercarriage and Right rear had bearing failure in 200 hrs so replaced whole idler in warranty, now at 240 hours has another, as you can see I do my best to stay away from normal stuff,
top line for right track
And with the old pump, with old regulators the NC was still 1000psi. I don’t think that whoever rebuild this pump messed up so bad. And I goofed up on RPMs babbling on previous post, I admit that! That was something around 3:30 AM, for goodness sakes!!!
After I clean out lines etc will test then move to pump, have complete old pump and took what Cat calls pressure actuators off side of pump to peek inside pump and look at shoes so if need different shims should have
Looking at the phantom view of the valve block showing the NC relief valve, part of the setup is the fitting that the hose is connected to. The phantom view also only shows a single relief cartridge on one side. The other side only shows the hose connection. TVA, the NC pressure is the calibration point used for aligning pump outputs and affect said output throughout the ranges of operation. It is part of what gives the machine fine control. Hopefully cleaning out the lines and fittings will bring the pumps back to proper alignment without having to mess with the regulators.
ok done with dozer, quick question why can I not switch lines from pump at valve block and see if pressure follows to other gauge, not hit any function just stay in neutral
Checking and cleaning the whole NC relief group and hoses that’s what we both me and you suggested like two or more pages ago. If you talking about my comments about RPMs - I corrected my self earlier and blamed waking up too early . Let see what cleaning will change. Both old and new pumps sow The same too high of a NC pressures, but who knows what those rebuilders set the flow at, having a good power to lift the machine fast on the boom down, without NC pressure going down to lower end can be seen as high “stand by” flow. In my understanding setting a stand by flow on the regulator is for overwhelming the capacity of NC drain orifice and other small leakages and replenishing empty center gallery and hose all the way to regulator spool in the timely manner, so pump can be de stroked. And the setting the stand by flow is not the primary mean of regulating NC pressure, which is supposed to be done by NC relief.
ok switched lines at valve body, not gauges, only lines, two ports on side main valve body, as pic shows the upper port is one with 900lbs pressure bottom one 450lbs, switch lines from pump and nothing changed, top port still shows 900lbs bottom shows 450lbs, so changing pump acuator hoses has no effect, is this a worthwhile clue?
Can you tell us what lines did you change?
As I remember before it was 1000 and 900?
Diagram shows NC relief s on both sections, so if one relief is not there than that’s an interesting development!
switched these lines from pump no reading change
Yeah! Let’s clean everything and see what happens, seems like every time those hoses taken off - something changes!
That’s actually can be seen as difference in stand by flow in regulators, but let’s clean everything first! I came back and re read the previous posts and one with the lower readings already dropped 200# Just with hose taken off and reinstalled.
With that busy of a schedule, you make me not only look bad, but feel bad too. You are one active guy. Sorry pump guy, it has to be done.
John, on the picture with OP pointing at the hoses, two smaller plugs, below the fittings - are those NC reliefs?
He said he wants to die awaken!
I don’t know about this valve block, but on Kawasaki at least one NC relief is on the bottom of the block looks like regular hex key plug. And the n Kawasaki pumps you don’t have to shim to adjust min. Displacement, it has adjust screw right in to the swash plate’s ass. Right Irish Kobelco?!?!?
ok reporting in--- pulled nc lines off side block, pulled boom spool 2 inspected -mooves fee up an down an rotates no friction, nice smooth looks excellent, flushed with diesel an air towards side block reinstalled did same thing to boom spool 1 same results on inspection, started an no change, did notice some stuff as I moved gauges where could see better, know ya'all get enough info you will know the issue start engine, at idle pump 2 has 850-900 lbs, full throttle goes to 1100, boom up an curl on right joy stick, curl in or out to stops idle or full throttle nc drops to zero, boom up at idle or full throttle nc drops to zero, boom down at idle with nc pressure at 900lbs bucket resting on ground ''slam'' koystick full down get instant pressure drop to about 200 then right back to 900, happens so FAST you have to be paying attention or will miss it, open to full throttle and push boom down goes from 1100 to about 950 then back to 1100, what is amazing is the down pressure is awesome strong, understand pivot point with boom down an stick etc but here in Fl. all we have is soft soft sand, get mad at somebody here have to drive to Georgia get a rock to throw at them....... so where reliefs? And cat had me pill little two line block in front of boom spool 1, what is that? I need pull? BTW got a lot more flow out of spool #1 thru side of valve that spool #2 when flushing.
third spool up is boom 1, right in front is little whickerbill with two lines going to it
This is sounds like either spool not blocking central gallery or something leaking to the center gallery when spool moves to boom down.
Me an wife swapped out rear idler and loaded for job tomorrow, needed too do something in our spare time this morning, hope this Taiwan made idler last
There ya go again, as I sit here lazy as can be. But, in my defense, its cold outside.
Have you checked your hoses to and from pumps for "flappers" ? When the inner jacket starts to separate and folds over causing an obstruction. Just something to be mindful of.
I would not get my butt up if it was cold outside, come on down need plenty good mechanics here, All functions drop to zero---swing both directions--curl both directions----stick both directions---tracking both directions---boom up--- only 4$#@%%^% boom down will not drop Started to check hoses like you said but swapped hoses at valve and did not change on gauges
Both of you just a “beasts” to pull off heavy job like this in your age!!!
Just went back and realized I skipped a few replies. Boom down is the only function without neg control drop to 0. That's fine. Unless you're hanging over an edge 30 feet deep you're never going to realize max demand without tipping the machine up on her butt. You have to see a load comparative with the drop in control. The only other way you could see this is to cap the hoses to the head or rod end of your cylinders. If you do this, and lean in on boom down, a couple things happen boom 2 shifts for added flow taking barrel side oil and shuffling to rod side. It makes up faster than pump can deliver when working with gravity. This will happen in the blink of an eye, cuz no make up is needed. Now the valve is gonna "think" you're digging in clay cuz it stopped moving, the pressure rise is gonna come in , the horsepower limiter is going to kick in . Your spool will be shifted all the way, you have a wide open path from pump to boom hoses, the oil is not moving, your negative control should be at near 0 for a moment before the pump destroke. As you play with the joystick from neutral to boom down, you should be able to view this phenomenon repeatedly. It will happen fast. No need to "slam" stick forward. That does nothing but abuse the swash plate and regulator. I copy and pasted the boom down function in totality from the info Nige afforded us early on. It tells you exactly what is happening and why. What spools and circuits are exercised and why. Are you still tracking straight, are your standby pressures equal? If the baseline is incorrect, nothing else will cooperate.
Reply 377 check it out. Its clearer than I can explain off the cuff. I think that with a better understanding of how the regulators work, thanks to mobiletech and establishing your standby & servo pressures is going to serve you well. Good luck.
Did you trace both those lines back to the pump? Usually one pump is on the outlet side of the main control valve and the other pump NC is on the other end of the main control valve block. Can you confirm that? So far you haven't confirmed anything about the fittings or where you have installed the gauges. You keep jumping to other stuff without completing the thought process on what you just did. Slow down some and think about what you have seen in the gauge tests and make an interpretation of what might be happening. You are waiting for someone to solve your problem for you and there are multiple voices here that are only confusing the process. Both funwithfuel and mobiletech provide good information but you jumped off track without thinking about the information that you were provided.
have hose coming off each pump accuator they go to the left side of main block as pic shows, before they go into block I teed in for gauges,
here is pic I posted showing hoses coming off pump, #4 hard to see letter 4 b/c light and #5 both go to main valve block, in pic to follow,
top one is forward most pump that runs boom and curl, bottom line comes from rearmost pump,
Still left with pump chirp the way it all started before, gauge is screwed into valve body, line from pump screwed into gauge bottom line from rear pump reads 450, top fitting in valve body has gauge screwed into it and line into gauge, top line shows 900 at idle, switch lines and pressures DO NOT switch, the bottom line to rear pump was reading 450 move it to top fitting now reads 900, move top line reading 900 to bottom it will now read 450, top port on valve and bottom port on valve keep same pressure not pump,
gauge hookup, so 1100 lbs of nc pressure does not have to be regulated down?
Not necessarily , yet. But more importantly post 393, how'd it go. Measuring pump pressure, do it at the pump. You have test fittings there for pump A&B . That's where you measure. Servo pressure correct to spec? Are working pressures correct? Do you have equal servo pressures to either side of boom 1 spool? If the spool is not shifting fully, not receiving the correct oil pressure , of course the control pressure is not going to drop off correctly Boom down , again , controls 3 functions boom 1, boom 2 and boom drift reduction valve.(some folks call it load holding or load check) if any of the three are allowing servo to drain off, or there is a restriction , your spool will not fully shift. BTW has this behavior started recently, something you've been living with ? I'm wondering if you have an option for grading that may have been inadvertently turned on.
The only pressure we should be measuring at the MCV is servo oil apply to boom 1&2.
See this is where i am struggling, can do whatever you direct me to do to gather information but i have been lost and learning as we go with this unit, this is my first ever excavator event, when I get back off dozer tomorrow will get each pump pressure , you want them at idle? full throttle? working? No it started month ago with slipper noise and had to finish job and got worse so I am one who tore pump up, that is why when I hear noise now I cringe, pump was rebuilt and sold along with a bunch of other closing inventory, spoke with guy who closed his business and sold it all to the guy I bought it from, pumps are stronger than ones on unit when I bought it, way stronger at low rpm tracking etc. where is grading option?
He is talking about reducing Negative Flow Control pressure in general, on a the pump that has 900-1000 psi.
Someone said here yesterday that pilot pressure has nothtto do with this problem when I proposed to check it!!!
He teed in to NC lines at MCV, and unless there’s flapper in the hose I don’t see the difference where it is tapped to - it is all the same hose from MCV to pumps controller.
Plus swapping the NC hoses proved that source of high pressure is in the MCV and not wrong setting of Standby Flow by pumps regulator.
Please don't interpret my statements. I meant servo. The oil that acts on the end of the spool to actuate a function. We are trying to establish whether the MCV is the problem or is one of the other 3 parts of the boom down circuit suffering a loss. If we can verify pressure changes as I have described in both directions, we can move on. Otherwise we'll have to pursue where the oil is going. I'm a simple guy. I started learning this reading Case manuals back in the 80s. One thing stuck out. This manual is written in CASE, clear and simple english. I have always tried to explain things in that same way.
If you're dead set on reading negative control tap in at illustrated points. None of this means squat til we establish baseline. Servo, followed by standby and working pressure. You can and should avoid full throttle for the time being. You have a piston pump, it'll compensate
Go to post 15 & 16 on your computer. Download both. Study the description. That is where I've been lifting nearly everything from. It tells where and what as well as why.
I had same idea as you: check the pilot pressure that moves the spool, the only difference is I called it actuator and you called it servo! It still activates by pilot pressure! I would do it right at servo/ actuator. Problems at this point is two: main one - NC pressure for one of the pumps too high! The instructions that Mobiletech posted provide incremental change of flow with changing of shim thickness at 340 psi. Although it is not direct statement but it only makes sense that what that pressure is supposed to be. Second this boom down NC drop, and I totally agree with you that we should ask OP to tee one gauge in to servo line right at the servo for boom down age leave one teed to corresponding pumps NC line and check if any correlation between two exists!
That’s interesting, OP traced his NC hoses to different locations from one on that illustration!
If you have the means , cap all hoses to boom cylinders. This will help us determine if you have a problem. Measure both a & b of boom 1 spool cap, exercise in both directions write down results. Perform the same test at boom 2. After you establish servo . 1 thing at a time. At idle. No need to shock the new pump. We want to fix the original problem before making another big problem. Now that I think about it, boom 2 must not be opening properly. If the boom is dropping with the speed to cause shoe lift, it is not allowing the barrel side oil to fill in the rod side with gravity pulling her down. Is this when dropping the boom or lowering at a reasonable speed? Just trying to get as much info as possible.
Funwithfuel, do you have Illustration to share with OP where he can find NC relieve valves? But probably not the MCV illustration of which you posted - OP has different port locations from that. I saw that this model has many different prefixes, may be different prefix uses different MCVs. At this point I think it is more important to get the NC pressure to normal value!
I do not. Nige made that available. I dont have SIS
He has power to boom down, so maybe you right and that’s the normal operation and system drops the pilot pressure to not to slam boom to the ground ( although I know lots of people who likes to do that, specially in the rocky soil, or to break rocks). It’s something that CAT people should respond on.
According to the front page, that is for his machine. I don't know why Cat would deviate from published materials. They are very picky about stuff like that. On top of that, Nige is very particular about posting incorrect or inaccurate information.
You’ve seen the picture of his hoses and ports, and his set up is functioning. I guess gonna have to do “reverse engineering”, start at return port and look for them!
Has this gotten anywhere yet?
I think I found one, it’s the bolt looking thing on top from ports in the OPs picture of Gauges.
And there’s another on the bottom of MCV.
Fugetabotit. Focus on what matters. No, I don't think it has.
Floridamechanic says the machine is better now that with the other pump. He says the only issue is that the travel on one side is slightly more powerful than the other. He is better off than when he started. Put the machine to work and earn some money back for all costs that have been accrued to this point.
MCV tag
may help---is that the relief by the tag?
Just to confirm, the testing & adjusting material in the post to which FWF refers was lifted straight from the online information system using the full machine Serial Number given by the OP in his first post on Page 1. Like FWF I'm pretty sure it is correct, because it's been out there for so long. I would have thought it would have been updated long ago if there had been an issue with it not being correct.
Well happy to report have boom down zero NC pressure, thank you one and all for all that you did, will be a full time member and try to help someone like ya'all helped me. Thanks to..... Nige---John C--CMARK--MOBILTECH--FUNWITHFUEL--TVA---VTECH 63---Delmer--UFFEX---Jonno634--CATKC--BlueOx---Kobelco Ireland---- Is truly appreciated that you would take time to help.
Summary of final answer?
This thread has been so helpful I was kind of wondering that myself
This is worse than waiting for the end of an Alfred Hitchcock movie .........
I test drove a 315b looking to buy and it would only lift the tracks 4" off the ground as you said and the only way it would go higher was with the boom down function. I showed the owner and he tapped the display panel, (it was set up for priority to Aux. Power) he pushed the normal dig button and everything went to as it should be. Just my experience. Best of luck
sorry guys, been juggling work an my excavator entertainment event, pulled relief next to tag on MCV, looked good and clean, went an got a tip cleaner an could not run it thru holes in relief tip, was 80% stopped up, could not even see the obstruction, see pic, put back together an presto boom down drops to zero, NC pressure is too high but was no shims in cap on relief, now has 850 lbs on this pump and 380 on other pump oil hot, still gotta get pressure down here pic
thanks alaskaforby4 will check
It sounds like you are possibly going to be in contamination issues for a while yet. Something is circulating in your hydraulic system that's for sure. I suggest that you go back to my post #267 on Page 14 and follow the recommendations contained in it. It will give you proof positive whether your system is "cleaning up" as time passes, or whether you are still in problems. I don't want to be the harbinger of doom here but how does anyone know that the pump you changed is the only thing in the whole of the hydraulic system that is taking a dump at the present time..? Only oil analysis could potentially confirm or deny that IMHO.
That 380 after first return filter change may come down to 340 like it supposed to. The question is this contamination is result of previous pumps catastrophic failure, or the contamination what killed the previous pump?!
I think that after evening out NC pressure on both pumps and checking pilot pressures at all four travel servos, and everything chefs out, then that weak motor needs to be looked at.
As mentioned, i’d Put it to work if you think you’ve got it mostly done (and see if you can narrow down the quirks). I’d change and cut filters after 3 days and inspect, to make sure things are settling down,
Earlier Mobiletec showed a picture with instructions for adjusting minimum stroke on the pump and it showed adding or removing shims to adjust that. Please note that the opposite side of that combination of spools there is an adjustment screw with a lock nut. This is similar to what is on a 330C excavator and NC pressure can be adjusted there. Turning the screw in decreases NC pressure on those machines. I don't know if that has a slotted screw or an allen head. In either case put a mark somewhere for a reference point and then turn the screw in a full turn and see if pressure on the gauge changes. If it does, bring the pressure even with the other pump and then try out your functions.
So glad you found something. Not to pile on, but yeah, moving forward those little gremlins may reveal themselves here and there for a bit to come. Hope its minimal and GOOD JOB!
Vetech will be disappointed, we only made 24 pages, nowhere near 61.
Negative flow control pressure is created during the following machine operating conditions. All of the joysticks and travel levers/pedals are in the NEUTRAL position. Any of the joysticks and/or travel levers/pedals are partially moved from the NEUTRAL position in order to perform a fine control operation. A boom lower operation is performed alone. I found this statement in sis interesting after reading that you got boom down nfc to 0 psi.
I’m disappointed in all of you. LOL
Hey mobiltech, go down slow it does not stay at zero, comes back up, but drops quick if you open flow, has not done this, it matches other functions is kinda way to say it, really do not have a lot of ''boom down'' room on boom ground gets in the way real quick, know that cleaning debris made it drop 6 to 800 lbs,
Tomorrow I get off dozer an outta swamp gonna hook gauges back up an get warm see NC pressures and then swap NC lines at MCV and see if pressures move with lines or stay like they did when I swapped before, thoughts? suggestions? Yes John C have allen head and can mark twist and see results tomorrow
Oh wait, it ain’t over yet........
Going to equalize pressures with shims first thing this afternoon, bet the builder did not have test stand to flow/pressure test and set pumps after rebuilding.
By the way those pieces of material that you pulled out of the relief valve or they Iron or bronze is hard to tell from the picture checking with a magnet to see for sure
This should hit 40 pages just trying to figure out where that contamination came from.
----"Amen brother, preachen to the choir".
I tried to read newer manual for Rexroth A8V pump once: it was like that thing was first translated from German to Swahili, then from Swahili to Maori, and then from Maori to English ( or even had some more languages in between). But then I found older publication - and everything became clearer than a day light!
How about putting some large magnets inside tank, have had good results doing this over the years to catch that last bit of metal and maybe anything in the future.
Most return filter have magnet stacks in center of filter to catch wayward junk.
Cat don't have magnet in filter
Well, I did say most
I don't think that has any magnets in the return filter, I have never seen any magnets on any of our Cat excavators older or newer than that. It is a great idea, could put them right on top of the suction strainer, would be easy to keep an eye on there. I think I might try it myself on one of ours, a couple cow magnets would be perfect!
I tried to read newer manual for Rexroth A8V pump once: it was like that thing was first translated from German to Swahili, then from Swahili to Maori, and then from Maori to English ( or even had some more languages in between). But then I found older publication - and everything became clearer than a day light! -----Reminds me of when komatsu 1st started coming to the US and their manuals
No! No! No! Not on the suction strainer!!! That thing gonna look like furry animal in a heart beat! And it’s gonna plug up even faster! Keep those magnets in the tank but away from strainer! Return filter is the best place for it.
Have to remember that the relief valve that OP cleaned lives right downstream from pumps discharge, the only thing between is MCV center passage. No filters or anything in between. So whatever pumps spits out - reliefs gets it.
hmmm "cow magnets" must be someone else here who's smelt a little cow **** over the years. It's a little old school but it's worked for years. Koehring did it for years, that's where I 1st got the idea.
Go on fleebay and order a bunch of salvaged hard drive magnets, they're much more powerful than any cow magnet I've seen. If they're still attached to the steel backing, use two vice grips to twist the steel and the magnet will pop right off without breaking.
I used the same magnets that use for wide load signs on lowboy, put them in tank in several locations,
Drained and filled with new oil and new filters and cleaned screen, real light brass just a little bit, no other metal, will cut filters tomorrow, both pumps hold 5k, pumps in neutral guess call it standby pressure is 1100,pulled relief valve blew out passage and checked was clean clean, screwed smaller screw out up to 3 turns no drop in NC pressure, will pull acuator off old pump tomorrow and learn how to re-shim then pull this one off,
You are supposed to turn the pump adjusters in to lessen NC pressure. I believe adding shims with increase NC pressure. Aside from all that, how is the machine working? Brass won't get caught by a magnet.
yes I know magnet will not pick up brass, one of those just in case deals, will try turn screws in tomorrow when get in, mobiltech post on page 20 says remove shims lower pressure, only 4 bolts hold actuator on so easy to remove, machine good and strong just has the pump chirp on boom and stick functions
I know you know. It was just a reminder to others that the failure was brass slipper feet and not a total catastrophe with shrapnel throughout the system. I just suggested the screw because it was easy and quick and could go back to original position with little trouble. Good Luck Tomorrow!
Is there somewhere it’s says what that flow or pressure supposed to be?
For the 330C models it was in a different book.
I’m actually looking through few pages for 300 series of D generation, it uses the same pump, bigger models using Kawasakis, but it’s only few pages that friend forwarded to me. So all the settings values in different book?
You have two books for Caterpillar Excavators concerning the hydraulic systems. The first explains the operation of the system. The second book is testing and adjusting. For the 330C max gpm at minimum pressure to a function is approximately 61 per pump. Gallonage in neutral with a NC pressure of 340 is approximately 38 gallons per minute. To give a little off set to this, a Komatsu PC300 at minimum flow all controls in neutral is about 12 gallons per minute.
38 gpm! That’s a lot! What is a displacement of that pump?
I think it’s the way to go without this thing, it “feels “ like there’s WAY too much flow in. neutral, but it’s only a “feeling”.
I took a look at some info, looks like we need RENR5519 in full.
thnks JohnC will try turn in and if nothing will pull shims, and report back this afternoon, will finish dozer job this morning so will have a lot of time next few days to work on 315
John, can you look in to your 330 book and see if it says what is stand by pressure ( at pumps system/discharge/supply) should be? At neutral it supposed to be the same ( or very close to ) as NFC pressure IMHO!
Here is the nfc flow at a fixed 340 psi. You would need flow meter and fittings to do this but it gives you an idea of the output .This is at 2150 rpm There is no adjustment for the nfc relief. It is just there to take out pressure spikes. The only way the nfc will be high is if there is a blockage of the nfc passage or your pump flow is high ..i would normally think a rebuilt pump would have been tested but because of the supplier im not sure. Im also wondering because of the tracking being off which is quite often affected by nfc adjustments . If you could swap main pump outlet hoses and nfc hoses that would tell you a lot. Negative Flow Control at 2350 kPa (340 psi) Oil Temperature °C (°F) Right pump Left pump Engine speed (rpm) Right pump Left pump Flow measured liter/min (US gpm) Right pump Left pump Flow corrected liter/min (US gpm) Right pump Left pump Specification for negative flow rate liter/min (US gpm) New 82 ± 10 (21.7 ± 2.6) Service limit 62 (16.4)
I would not recommend adjusting the screws opposite the nfc shims ..that is pump horsepower adjustment which affects how it reacts to pump delivery pressure and pump regulating pressure from the prv solenoid .That will do very little to help nfc pressure and flow .
The two screws on top is - one minimum displacement, the other - maxim displacement. You have to have some minimum displacement for the whole thing to even start working. But the flow adjusts with shims by stifenning the NFC spring, which will lead to pump being begin to destrock at higher NFC pressure, which in turn leads to higher stand by flow. I finally got some information on this thing. Thanks Mobiletech!
I have the theory that difference in NFC pressure is because the higher side has only four spools in that row, but the lower side has seven spools. More spools, more surface of crevice more means to dump the excess flow. Stand by pressure is identical between two pumps because of cross sensing passage between them which used for total horsepower control. The only thing I can’t explain (yet) is why it’s stays constant across all range of RPMs.
Is 2150 are those RPMs? Or another pressure for another flow reading?
Sorry! Just pryed my eyes open! They were still watery - couldn’t read good!
Yes top screws one is minimum one is max . Nfc pressure is unaffected by how many spools there are. Yes flow increases as you increase nfc pressure adjustment . Pumps are affected by 3 things. 1. Total output pressure in cross sense passage in pump head 2. Prv solenoid pressure which is regulated by the hyd ecm sensing engine speed monitor settings and highest pump pressure signal from pressure sensor on pump . 3 .Nfc pressure which tells the pumps that there is no demand for pump output . I am taking this info from what i have learned in 30 years of working on cat excavators ..i learned most of it through field testing and Cat training at a dealer for 20 years. Am i always right .No. But ive seen enough problems to form a pretty good hypothesis with limited info and no way to get a hands on feel of what its doing . I am a lot more successful if i can see and hear the problem firsthand. Post another video if possible.
I hope Uffex documenting all of this in to archive, then systemazation and at last - bulletin!
ok, just got in, how about if I pull actuator off old pump and put in on this pump[clean it up} or should I pull right actuator and pull shims and reinstall and test?
I would suggest against it! There’s other settings there that should be done by rebuilders ( but who knows if they did it)
Come on guys...……...I feel like you all are DELIBERATELY stalling this thread to prevent a new record. Its total BS!
Slow up Vtech63, have a whole lot more info coming this afternoon, just pulled bottom relief an ........be back later........
Here we go, first swapped electronics on pumps just to see any difference-was none second bad as hated too pulled belly pan and pulled bottom relief, port holes plugged , cleaned and reinstalled, did good till oil started warm up then noise started louder and louder,pressure was still at 850-900 idle and 1100 wot, pulled actuator off old pump and took apart, had two shims under relief, had to pull actuator of pump in hoe as no room to pull valve, pulled valve had two shims, 1.30 mm and 1.45mm, left out 1.30 reinstalled actuator, went to 750 at idle and 1000 wot, pulled actuator and removed last shim of 1.45mm to test results, no change, 1000 at wot and 750-800 low idle, right track still strong track it is noise track also in video, slow crack function pump chirps bad, open function more get past chirp gauge drops to zero and no chirp, once NC pressure drops b/c valve open to drop pressure has plenty power and no noise, stretch boom out and has more than enough pressure to raise unit, not going to run anymore than necessary just wanted to show what it is doing, with track in air and barley crack function NC pressure stays high and chirp is alive open more and as soon as NC drops to zero chirp gone and lots and lots of power,
This is EXACTLY how started on last pump, had to finished the job and blew pump, makes me think in MCV, excavator has never had as much power as it does right now, prolly 20% better than ever,
With what you have found in the mcv and still have the same problem Id jerk that mcv and go thru it with a fine tooth comb. Before this pump shoots craps. What is it 2 or 3 valves in the mcv that you have found stopped up with some kind of foreign debris.
It makes sense. If the orifices or port reliefs are becoming plugged, you lose the safety margin in those circuits. I think, if you're not gonna take her to auction, you'd better go through the valve and disconnect travel motors to flush those hoses as well. I know this is a lot of work but it really needs to be done to prevent another pump failure. Hopefully with all the cleaning, no additional parts will be needed, nothing more than O-rings that is.
What did u found in MCV ,any pic of it ?
little small particles off slipper shoes only brass flakes is all I have ever found
So from your video I take it that only one pump and one side of main control is noisy? I think you have a blockage in the nfc circuit and what you hear is the nfc relief valve popping open causing pump flow to be very erratic until the oil can finally go through the main return passage.
It seems there has been either a past contamination failure, or a current one is eminent. Without a total breakdown and cleaning this is going to happen with functions forever. There is way to many places for contamination to hide throughout the hydraulic system to have any proper fix here. It wouldn't surprise me if this machine was in an auction in its past history.
Where the problem is. In the pump or in the MCV.
Mobiltech I think you are 100% correct, have worked machine hard for over year and no problems, put a prv on and external ground strap b/c 315 ground issues, just tested standby pressures and got big clue and suprise, have been wrongly thinking it was forward most pump all this time, hooked gauge up to forward pump, standby has 400lbs at idle and 550 at wot, this actuator I pulled 2 shims out of, hooked to rear pump and standby has 1000lbs at idle and 1600 at wide open throttle, all these reading are in neutral no functions activated and did pull lthe actuator on left pump this morning and removed the two shims just like other actuator, so have extreme high nfc on left pump, think your bleed down theory correct, this machine was county machine that why low hours and according to my ET scan ecm matches gauge
After watching your video, we have a 450 New Holland that started doing that. Almost identical sound. It was a contamination issue. There was a coating on the inside of the hydraulic tank and it started coming off and going through the system. Took forever to figure it out.
Mobiltech any way to narrow down where to look for blockage in nfc for rear pump? I know I am too old to pull the MCV, will not patch and send to auction, just not going send someone else my trouble, not my way doing things,
You could pull that nfc relief again and see if you can flush it out. Remove signal line on valve at the same time and blow back through . chase the passage with something. After all this playing around just make sure you havent got your nfc signal lines crossed .
With a problem like this you have to be thorough when testing and cleaning. Follow schematic and double check your connnections .
Well lets put this one to bed, ole HTS pump was the issue, just asked them if folks in Mississippi had sense humor, they wanted paperwork on new cooler for''warranty'' sent them the pics of their rebuilt pump and explained they prolly will not be getting paperwork, requested they refund all my money and would let it go, chirp gone both sides 350 nc pressure, actuator was unscrewed not letting it travel, cheeezzzz what a road, comments more than welcome
So your pump regulator is full of rust? Piston stuck/seized holding displacement in place? Holy cow. That's terrible. Glad you found it, sorry it was such a long and difficult journey. You better take care of your woman after all this. (If she stuck around )
Hey FWF I been working on dozer she is the one who found excavator trouble!!!!! She said same thing so guess will have to pay her lol
Well, there you go. Take that girl out to dinner. You said in the beginning, you'd pay the one who found it, so pay up. She deserves it.
Wow .What are the chances youd get a pump that would mimic the problems of the old pump. That explains the tracking issue. I wasnt sure how a blocked nfc passage was causing that . i thought you had a rebuilt pump .Dont you hate it when that happens .
Yes it has been an experience, now gonna have some fun with ole boy, he does not understand the power of the internet, but brought it on himself, now it tracks straight and true,
Wheres my 63 pages?!
Well I am sure trying do my part, all back together and go for test flight, did not crash but had to limp back runway, beginning to think have a bad relief valve of NFC, get warm and under big load or full function and hold get chirp, strange part is while ago had bride boom up all way and hold, bogged motor hard but no chirp, next time no bog and chirp, standby pressure both pumps 350-400, main relief kicks in 5200 both pumps, pilot pressure 500, need pull nfc reliefs see stopped up and if not could one be bad and root cause of all my trouble?
Have you checked your negative flow control lines going back from the main control valve to the pump. I would be looking for flappers on the inside and kinks from the outside
will go do that first, no kinks i already looked, flappers check????? air hose??? lost here
When the inside jacket of a hydraulic hose starts to skyve back, With sufficient oil flow it can block the passage. Very difficult to find very frustrating because you cannot see it. You almost have to measure at both sides of the hose to verify or just remove the hose and cutting open to see but then it's garbage
so best just get couple made eliminate off list, common occurrence on nfc lines? reckon relief weak?
https://www.hydraulicspneumatics.com/hose-tubing/guide-recognizing-causes-hose-failure Take a Take a peek when you get a chance scroll down towards the bottom a little . It will illustrate what what I'm trying to explain a little more clearly I wouldn't say it's common it's just that I've been burned a couple times in the past by missing them I refuse to let that happen again
I understand that will get couple made and go from there,
Did you say you moved the prv solenoid from the old pump . I would be checking the prv at this point ..it will make engine lug come and go. It could be contaminated. Ive seen where the prv will cause pump chatter. Put a gauge on it and do a sweep test and calibration.
ok mobiltech got new hoses made going install and see can figure out how do sweep and calibration this evening, man I sure thought was done, update new hoses installed, no change, at least took that off list,
Sweep done and calibration done, Took me longer to figure out how do it with Cat ET than it did to do it, no change, still chirping , go full function on joystick and hold or load hard, put throttle control on 3 and stick in and hold it barks go any higher on throttle gets real loud, lot of power, stretched out boom and bucket will lift machine right up in air,
Ok just for my education '''''what''''' is making noise? Sat on MCV and had wife set throttle at 4 and full retract stick then hold in and make chirp, it is coming from pump, so is it the shoes bouncing? Set throttle on 1 put boom down in front machine and boom down will raise machine all way no noise,
Noise is after stick in all the way in, correct?? No noise, while moving? What about if you run all the way out and hold, noise? Did you do throttle position 1 and move stick, what were results? Any noise with throttle 4 and boom all the way up? Sorry, your last update seemed to compare apples and oranges.
I'm wondering if you are hearing a snubber. At the end of stick travel at the piston end there is a little doo-dad that shuffles oil from barrel to rod and vice versa, but only at end of travel. You should see a noticeable yield as opposed to a harsh stop at end of travel. I don't know that your machine is equipped, but I wouldn't be surprised.
position 1 stick in/out all way chirps, position 4 boom all way up big chirp, this noise is exactly how it started before, seems to be functions when both pumps are needed ie stick/boom ( ps grew up in Naches wa.}
FWF, no sir i know what you are saying, this is from pump,
“ps grew up in Naches wa.” Ha! Ha! Ha! This is a GOOD one!!! But someone who never been to PNW would not get it!!!
Could it be the pump destroking? This chirp, it occurs at dead head?
Gonna hook multiple gauges up and see can gather more info this afternoon, see if when noise occurs have a needle bounce on either pump etc,
throttle control set on 5---stick retracted full in and hold stick in function full back it starts chirp, same with stick out or boom up, digging load stick or pick up heavy bucket full it chirps, this is what it did before and got worse quick till knocked shoe off--gets real real bad as you add throttle, sorry about the yellow gauge dropped it and lost oil so put some wifes olive oil in to make video
It almost looks like your relief is having a hard time. Instead of purging steady, its surging. If we had a flow meter in place , I think you would see surges in flow coming out of the pump consistent with the sound you're hearing. And when that noise comes in, yes, I think your slippers are losing contact with the swash plate.
Like it is holding 200-300lbs too much? Have heard of reliefs getting weaker but have not heard of one getting stronger, have you? Could it be sticking and taking more pressure to open? Gonna pull this morning and examine
Have you gone through and set your pressures. In other words, did you increase your main beyond port settings, set all your port reliefs and re-establish main. If you have a weak port relief it could be competing with the main. The only thing that is gonna cause pressures to increase is a restriction or obstruction at the main or port, such as you had reported finding earlier.
I would inspect your main relief for debris and turn it down a bit. Could be port plate separation in pump at high pressure. That’s when the barrel lifts off the port plate at high pressure. Check your case drain pressure while this is happening. When the plate separates you will see a spike in case drain flow.
results--- pulled main valve, took apart tip has small screen, real small, took apart an cleaned and backed off 3/4 turn, installed, no noise stick in, but pressure way to low[did not know how sensitive it was] removed and backed off 1/8th inch was at 5k so I pulled again and backed off smidge more now full retract on stick and hold is 4800 and specs call for 4920, but no change stick full retract or boom full up is exactly the same chirp and needle drop just like was on video Bad relief?
Check case drain pressure or flow on pump when noise occurs.
ok
Do not have flow meter and could not see anywhere tap into case drain for pressure test, need get flow meter? what is cause of port plate separation?
You could just take the case drain hose and extend it with another hose so you can run the case drain into the top of the tank or into a pail. The flow will be very little ( A couple gallons a minute )unless there’s a problem. Causes of port plate separation are many. Weak barrel spring , uneven barrel contact , loose bearings , warped plate, over pressure, case pressure, viscosity wrong. The only thing we know for sure about your pump is that it has not been rebuilt and may be a core return from someone who was having problems with it on their machine.
seems strange it is doing exactly the same as other pump started, my thoughts are something is out of whack that ''controls'' pump, this pump has way way more power than my old one ever had, can wind it to wot and use all functions and no noise now that I fixed the standby pressure issue, but hold it full open on dual pump functions it will chirp, took it to dig place and if you load it hard hard it will chirp, that is how this all started had the big heavy rake on pulling palmetto's out when it started, ordered a new cat prv this morning just in case it is out of whack, it calibrated and passed with ET but who knows? will try the case drain to bucket deal in morning,
Did u take the old pump apart ? Where did u get they new pump ? Did u change filters after pump change ? Did u change hyd oil after pump change ?
4 times filters an over 200 gallons hyd fluid
what about old pump ? what was wrong with it ? any pics of old pump ?
How about reading the thread?!
Ahh! Crap!!! I’m being an ******* again!!!
Sorry. Im just tryi ng to make the best of tricky troubleshooting without hands on testing . The case drain test is about a 15 minute procedure that should comfirm whether or not we can rule out the pump .
Who wants to proofread 29 pages looking for an answer ? This aint history class .
Thread need cleaning up
Where’s Vetech63 when you need him?
Mobiltech, going do case drain test now, turned around and came back home since you said not alot of oil will do the bucket thing, is it possible to have a restriction down stream from case drain at filter? blew air threw lines and several new filters, has line from swing motor tee in at case drain, will video drain test give me 20 min and one borrowed neighbor kid lol
Well I’m in a good mood today, but someone trying to pull my inner ******* out. I don’t want you to lecture me again!
this is with wot and boom full up and hold---- forgot to add no chirp with line in bucket wide open throttle boom full up and hold oil warm dual pump function
I would say that is more oil then you want coming out of the case drain.
pulled plastic check valve out of filter housing, crazy setup, filtering maybe 20% of oil rest going straight to tank, anyway pulled out and started does not chirp, you see case drain at idle, is about 3 times that with both pumps stroked wot, no pressure to speak of just flow, say this b/c hard to tell pressure from video, just measured oil little less than 3 gallons in little under 30 seconds
I would say: need to test the pump - it is both pumps at around 5000 psi. With controls probably trying to destrock the pumps by PRV and Horsepower controls. Destrocking done by draining one side of the servo piston to case! Need to run “constant horsepower flow” test on each pump separately to really know for sure the “health”of the pumps.
Ok just did what TVA said do, run constant horsepower test on pumps, worked it hard , dig swing walk etc for 20 minutes, no chirp, can tell when hold against stops machine is not straining now, works with more power on 7 than it did on 10 before, hyd oil is running cooler also, gonna order new check valve and compare, it is really a self adjusting restriction, pics are of closed and held open spring collapsed all way ,
here pics, it split, I am like TVA I bet it was one piece and that is what restricted old pump, and was going to get this pump, thanks to Mobiltech insisting on case drain test and TVA having me pull filter housing and check for restrictions the chirp is gone, we sent case drain video to pump rebuilder and asked him his thoughts and he said with both pumps wide open it looks absolutely normal, which was a ''relief'' (get the joke?),
LOL...…..that wasn't a lecture, it was more of a pimp slap . We are good my friend.
NOOOOOOOOOOO.....we AINT fixing this in 30 pages!
I was expecting to see a heavy shot of case drain flow when the chirp was occuring but no chirp is a good thing too .If it was just internal leakage you were seeing there i would consider that kind of high for case drain but if you add in control valve drain flow its not really bad.
Thanks Mobiltech that is exactly what guy who rebuilds pumps said,