Hello I just bought cat 963c serial # j2ds02378 It is moving at very slow speed forward and reverse and doesn’t change when you shift it to high rabbit it has few stored codes and only one active they are Active- 030 0271.05 Stored - 030 0248.02 079 0110.03 079 0110.04 079 0349.05 Any help would be appreciated not sure where to start it holds 2250 rpm pretty steady might drop 100 if pulling hill trans oil is full and clean looks good figure will change it anyway when I service it just not sure if any these codes might scream an obvious problem to some of yall thanks
I would start by doing calibration first engine off then engine running when you do the running make sure you have a long clear area setting high speed is a little unnerving
One more thing only go to 17 you can check engine speed and charge pressure do not put it in stall if you hold it in too long it will smoke the port plates
That's for the Action Alarm - the warning beeper that accompanies the flashy Master Fault Light in other words. Before you dive into calibrations it might pay you to familiarize yourself with how a Click Box operates. You have one built into the RH armrest of your loader. See this THREAD for more information. Post back with any questions you may have. Electronic versions of the calibration procedures might also be available. The Logged Codes you can erase with the Click Box. It might be a good idea to do that then see what, if anything, comes back.
What is process for clearing the service codes
Go to mode 3 to get the codes then use the clear switch
thanks will try that and see if I can calibrate everything will let yall know what I find
Click the link I posted above and read up on the Click Box. It's all there.
We’ll update I completed calibration all the way up to 17 maximum track speed and there I could not get machine to gain any speed in 6 at all no matter how many times I clicked increase and now the trans warning light will illuminate when you hold it wide open and stops machine if you move to park it goes off and machine will move again until you move the speed control back to more than half no new codes I’m assuming this problem is self inflicted might try start process over again and see what happens
Check your charge pressure
I see you are from Missouri. Are you remotely close to STL?
Summersville about 4 hours south west of St. Louis
I tried to redo calibration again and same result all goes well until try set maximum speed and there is no speed change when clicking increase at all ran it quite bit to warm oils before starting process and realized trans temp gauge doesn’t seem to be working when checked it in mode 2 shows 51 degrees Celsius just not showing on gauge don’t know if that could be related problem or not I have no warning lights or anything on dash this morning and still just service code for the alarm buzzer
You will have to excuse me I have done the tests so much I skip alot of things that I should tell someone just starting. First you don't have to go thru all the calibrations you can just go to 17 for track speed. 2 The tap for charge pressure is on the block with all the solenoids under cab it will be marked. At high idle in park it should be 355+- 7 adj to high side of spec. 3 The relief valve for charge relief is on top of the same block, There is a cap over the adj screw do not loose it it has a finer thread than you have ever seen, Loosen jam nut that is under cap the adj is done with a allen wrench at top of stem only do small adj at a time. Iwould put tractor at high idle and adj it. Let me know it it won't adj up
A little too far away from me. I am a little over an hour southeast of stl. Do you have a service manual for machine? What does it do when it fails high speed cal?
No service manual yet I plan on getting one but just purchased machine yesterday and what it does in high speed cal is you can click it up as many times as want and no speed change if you do it a lot it eventually throws trans warning light and stops moving until you cycle to park and back again then will move short distance and repeat that had to reset everything to get that to stop but still no speed and thanks Pittsburg cat man I will try that and thanks for explaining that lol I was a little lost on what you were telling me but now I understand thank you
Are you performing the calibrations with machine blocked up and tracks off the ground or on flat level surface? I do not have a book or SIS with me but do you know if that machine has one or 2 track speed sensors? You went through all of min speed forward AND reverse and the synchronization procedures all the way through? What is charge pressure doing while when trying to move all out? How far apart were left and right track speeds before performing calibration?
Yes on flat ground or as flat as I can find here not on blocks I also studied up some and realized that when I get to step 17 setting max track speed book says the far right numbers on display should show speed and all mine shows is 00 at all times never changes could this be pointing to the problem
I e also noticed rpm’s drop from 2225 to 2150 when moving read that reduced rpm could also directly affect speed but not sure if that’s enough of drop to count or not
Engine rpm should be 2335+-50 at high idle no load might check cable adj if it is low. Also does your machine have a cab might want to check if center pedal is up the whole way with out a cab they get pretty sticky.
Yes hard to set speed when it's showing 00. We never got good results doing calibration up on blocks always done them on ground
Yes has cab and I will check the throttle because best it will do is about 2225 rpm sitting still
Made quick adjustments to the cable got it roping out at 2335 rpm now and still same problem so not lack of rpm’s
You need to check charge pressure also I was thinking it might take a while for track speed to register try pulling it all the way back when you start
Yes it could. Can you get any speed readings at all in submodes 22 & 23? Note the reading will be unreliable below about 3mph. Can I suggest you unscrew the hydraulic filters and tip them out to look for gold paint? It may save you some time.
Got exactly 355-358 charge pressure at high idle in park just found gauge and checked it
Just dumped filters and everything was clean looked good to me no metal shaving visible anywhere also tried calibration again and found step 6 when synchronizing tracks at high speed there is no response no matter how manny times you click adj up or down it just tracks straight no matter how many adjustments in low speed sync you get a pretty immediate response and can make it track crooked and then correct with just few clicks back but nothing at high speed
Also Cmark there are no speed reedings in mode 22 or 23 either they show all zeros 0.00
Charge pressure was perfect right at 355-358 in that range
Interesting I would have bet on it being low. I believe I would block the tracks remove little covers at center of final drives and pull both axels put center cover back on go to submode 17 high idle full forward and see if you get speed reading. if no reading that way i would pull one of speed sensors they are kind of prone to damage as they only have one bearing on bull gear and the other side rides on a thrust button
Ok will try that tomorrow and let ya know what I find keep hoping it will be something simple and not need new hydrostat trans
Another thing maybe worth mentioning is when moving speed direction lever it gains speed both forward and reverse up to about the #3 or 4 position and that’s where the speed gain stops might mean nothing but moves same speed after that point no change
Hold that last thought you might want to check the sensor on travel control. I'm thinking they had trouble with some sensors i'm thinking old part number was 1471680and it went to 2144863 I don't remember having a problem with one in travel control but i had a few in steering pedals make me crazy! I beleve there was a service mag on the switchs
That's good. I think you need to get the speed sensors working. That's the point where the pumps are fully upstroked and the motors take over by beginning to destroke. Are there any hoses disconnected from the motors? Do the motors look like they have been tampered with?
I will check that out tomorrow and update yall I haven’t noticed anything unhooked but haven’t really looked the motors over good yet I will inspect them better tomorrow and check the travel control sensor as well thanks
One more thought put a gauge on one of fwd signal pressure and see if it changes after you get into higher speeds
Stuck gauge on right forward drive pressure port reads 320 psi at high idle park but my gauge isn’t big enough on goes to 1000 psi and it pegs it at about speed level 2 also don’t see any hoses unhooked on drive motors and looks as if nothing has been disturbed on them any time recent
Not drive pressure it is very high at stall kind of dangerous drive pressure is higher than what test hoses are good for the tap I wanted you to connect to is on block where all the solenoids are it will be marked rfwd and lfwd pressure will be in 300 pound range
I got ya I will try that now
Ok got reading right forward pressure is at zero high idle park and steady gains as you advance speed lever back and in position 6 for high speed it topped out at 218-220 psi
got same reading on left forward pressure steady increase as speed lever position increases and topped out same 218-220 psi in high speed
I'm thinking that is about right. lets try this pull the axels after you block track try to get a speed reading
Ok will try that you mean start and move lever forward position while axles are removed I’m guessing?
yep If we can get a speed reading we are going to cap signal lines to motors
Ok here what got removed axles from both sides and at high idle in rabbit there still no speed reading in mode 17 forward but in reverse it tries to read at about stage 4 and up in direction speed lever goes to .66 then falls back zero then when you change to position 5 does this again and in 6 also but no reading in forward at any position
Been playing with it little more and if you move from forward position 6 back to park for just a second it tries display speed at like .66 then zeros out
Maybe some tests of the track sensor, or maybe even remove it and check that the nose end isn't covered in metal shavings.? I may be wrong but it doesn't appear that the track speed sensors generate Diagnostic Codes if they are misbehaving.
Try it in moderation 22 and 23 mode I hate phones
Ok tried it in sub mode 22 got a reading in reverse that was bouncing around between 1.20 and .33 just all over but nothing forward in 23 got no reading at all it tried one time in forward jumped to .08 then zeroed back and stayed
I think I would be checking harness and plugs for bad connection
Ok will give her look see and see what I can find
@pittsburgh cat man can probably confirm this but the sensors (#13) appear to be adjustable. On that basis I think I would pull the sensor for a look-see, clean the nose end up, and then reinstall it making sure the adjustment was correct. Also confirmed that the L & R speed sensors do not generate Diagnostic Codes if they malfunction.
I’m thinking 963 sensor doesn’t go in final I think it is on the top of motor and not adjustable
Well that image came straight from SIS based on his Serial Number. SIS has been wrong before though.....
I can see the wires going in frame like in picture I’m dropping belly pans now to get in see what I’ve got.
I must have been thinking of bbd serial number If they are going in final they have a better than even chance of being hammered by the bull gear
Yes got one out and cleaned up looks ok visually gonna ohm it if I can find my meter not sure how to adjust it when goes back in seen somewhere I thought screw all way in and back out 3 turns and tighten but but not sure that’s right
According to the electrical schematic the resistance of the sensor should be between 110 & 200 ohms at room temperature. To adjust, gently screw the sensor all the way in until it touches the bull gear. Back it out a half turn and tighten the locknut making sure the sensor does not rotate.
Thank you will do
I only have a 953c book it said 2 1/2 out after it touchs with axel in it was in system operation and testing and adj book
Finally got ohm meter run down and back in shop the left sensor read 144 so it should be good got it clean gonna reinstall now and check the wires and o Right sensor now
Good spot. For some reason I had segued off into the engine with the half turn adjustment advice. From the T&A for a 2DS-prefix machine. By hand, screw speed sensor into the hole until the end of the sensor contacts the gear tooth. Turn speed sensor in the counterclockwise direction for the following amounts: Speed sensor (Track) ... 3 turns Speed sensor (Engine) ... half of one turn
Ok got sensors cleaned and adjusted was gonna see if made difference and decided check hydrostat fluid level while checking engine oil before start noticed hydrstat was showing about inch above full on dipstick cleaned it checked several more times still same so I drained about gallon out looks more like engine oil than hydraulic got brown color and definitely seems thicker than 10 weight crawled out pulled stick and doesn’t even register now is that normal for one gallon make that big difference?
If you aren’t sure what it is I would suggest you drain the lot and start again with known fluid.
did you drain the case in front of pumps ?? If you did don't run it they don't hold very much oil
Yes the case between pump s and motor same case that oil fill tube goes in and dipstick and I havnt ran it didn’t figure on it until have oil back to full
I think it's about mt I remember it only holding about a gallon you were right it isnt hyd oil Nige might be able to tell you capicty and oil type I'm thinking 10-30 but i'm not sure
10W30 engine oil. The capacity is listed as 1.0 gallons.
Perfect thanks
I'm not sure but maybe if the cap was removed it might just affect the reading of the sight glass.?
I was thinking a bit more about this. The lubricant types/specifications document for your machine has not been updated in almost 25 years. I can see what Cat were trying to do, they wanted a relatively light oil when it was cold and increase the viscosity as it warmed up. At that point in time the only multigrade oils on the market were engine oils, so that's what they specced. This despite the fact that the soot and sludge dispersant additives in the engine oil were not required. But in 2025 there are multigrade TO-4 oils available and that compartment is a gearbox, not an engine. So if it was mine based on what I know now, I would put a multigrade TO-4 oil in it. Most major oil companies produce one.
You sure are making me think.The 973c s had a seperate tank for power train oil. I'm almost positive 953c and 963c got there oil from hyd tank. As far as the oil I wouldn't be too concerned about 10-30 there isn't much in the splitter box just 3 gears and 6 bearings
This is power train tank on a 973c I don't have any pictures of a 963c if you look in parts book under transmission charge lines you will see line from hyd tank to pumps
63C uses hydraulic tank oil. Have 2 2DS's and a BBD in shop as we speak one of them had an engine fire one finally came in for an engine overhaul at 26k hrs and the last one is a hydrostatic basket case and I might have to get some help from @pittsburgh cat man . You guys must see them a lot up in your area
Used to be a lot, before i retired they were getting replaced by excavators. We even had some remote controled ones in the steel mills. We also had a 53c that was in shop that ran underground it had a cummins powering it
Why a cummins? I am pretty sure all cat engines are MSHA certified. They used to be everywhere here too. We also used to see a lot of the 939's too but no one even makes a machine that size anymore...all skid steers now. I have done a fair amount of work to the straight 43 53 63 and the D and K series but went probably close to a year without seeing any of them. Now 3 at one time. It has always intrigued me how things seem to go in spells. My big lathe hasn't been powered on a couple months and now I have 2 different excavator cylinders to make in the same week from 2 different customers
It was pretty impressive they used the cummins because it had scrubbers on it i beleve it was a 8.2. At that time there was no dpfs on 953 s they also had most of the electronics removed and did it with hydraulics you have never seem such a mess of hyd hoses
I know around here the coal mines use a lot Deutz engines. It's pretty neat to see an oil cooled Deutz coupled to a 400 turbo transmission in an S10 built to be underground the rest of its life
Yes it pulls oil from hydraulic tank doesn’t have it’s own tank for drive system it’s thrown me for a loop I was used to my 943 b and this is entirely different beast
Speed sensors looked good I ohmed them and they were showing 145 which is in the range book says good I reset them and ohmed wires from ecm plug they show good my question now is this speed not registering even gonnna be related to my orioleoblem of slow top speed or am I chasing something that doesn’t matter
If you were only losing speed signal only on one side it might be worth a try to swap sensors side to side to see if the loss of speed signal changes sides or stays where it is. I dunno but I would say that if you have a speed signal not reading it could have everything to do with your loss of top speed issue. FWIW I would not ohm those particular wires to check continuity. If you have a wire somewhere hanging on by a thread then it could show "good" on a resistance check but not be good enough to pass a signal. I prefer unplugging the connectors at both ends, jumper one end of wire X to machine frame ground, then power the other end of the same wire from batt+ using a fused 3A or 5A test light. If the wire will pass that level of current it should be good.
I was mostly concerned about getting a speed reading to check the track motors destroking. I seem to remember checking speed sensors with volt meter using spoons into connector with meter set to ac milli volts
I keep thinking both sides not reading or partial reading makes me think a connector that has both speed sensor wires in it.
Update got everything back together and tested machine again still no speed register in any the submodes and now have a new code 079-0132.03 ?
I would have to go back and read systems operation again but I am pretty sure that the speed signals tell the controller how far to open the solenoid valves in the control valve so I wouldn't think it would move at all.
Override pressure sensor. See attached.
Having just replaced the harness on a 2DS00624 there is no connection between the speed sensors and the power train controller. Those wires branch off about 18" from the controller connector and run right down the RH side of frame and then splits off with one going to RH sensor and the other half gets tied to bottom of frame to the LH sensor. I will say that when I ordered that harness there are several serial # breaks so I can't say if his would be the same or not.
Well that was easy fix simply unplugged pressure sensor cleaned connection and cleared code I washed it yesterday to get better look at things guess got moisture in that plug
Guess back to trouble shooting speed sensors for now I will see what I can find what is the likelihood of bad ecm ?
This from the electrical schematic at the ECM. The track speed sensors go to various Pins on Connector B. The wires go through one major harness connector between the finals and the ECM. Look for CONN 14 on the schematic.
Found new issue retesting speed sensors found on b plug on ecm the e900 and e901are in b20 and b14 on plug but e903 yellow is in b23 and e 902 purple wire is in b29 this book shows should be in b24 and b35
Is it possible to switch them or is this possibly just not correct for my machine
So I knew I had a speed sensor I decided I would do a little testing I connected my meter to it set meter at ac volts 200m worked a small set of calipers in front of pick up it will read
Just had another thought the 7x6315 strap on Nige's ecm post is a little braided strap that connects ecm case to one of the mounting bolts might be a good idea to check it as ecm is mounted in rubber
I would believe the schematic, especially if there is no obvious indication that the wires on Connector B have ever been interfered with in any way. The sensors you mean., Sure it is, they are the same Part Number. Just switch them side for side, set up the adjustment correctly and see if the problem stays where it is or follows the sensor that's currently reading 0.0.RPM.
If you are swapping sensors I believe the engine speed sensor is the same also. I am assuming he reading his engine speed via the display so which would mean we know that sensor is working correctly.
Same Part Number.
That’s what I was thinking it looks like same sensor might try swapping it and see if I can get reading that way ! I tested wires from ecm to sensor like you mentioned nige and they test good all way to ecm plug but still no reading was looking back at testing procedure I’ve been skipping first test unplug sensor and test from plugs to side case said should get reading of 10000 or higher I get nothing but test across the plug prongs shows good ?
In truth you should get open circuit. On my meter it shows as "OL".
That’s what mine says also
Do you have a set of spoons to back probe wire connectors? I would try to see if you get a reading with meter set on ac volts 200 mill at the ecm plug (1) pin20 and pin 14 (2) pin 29 and pin 23 while the motor is turning it should very as speed changes. If you get no reading there do it again with spoons at speed sensor plug
For Step 1 you unplug the sensor from the machine harness and measure the resistance from the sensor body to each of the pins in the 2-pin connector in turn. You should see "OL". Step 2 for the sensor resistance we already know you got good results. Step 3 the sensor is reconnected and the ECM is unplugged. You then measure the resistance between E900 & E901, and then between E901 & E902. It should give you similar resistance results to what you got on each of the sensors in Step 2. What did you measure.?
That’s exactly what I did and that’s exactly what results were OL on step 1 and step 2 and 3 were all same readings around 145
I will see if I can barrow a set and try that
In a pinch I have used small pieces of mig welding wire cut at a sharp ange with some side cutters and used them as probes. Even .024 wire is small enough but stiff enough if you are careful inserting with needle nose pliers
The little gears are turning in my head again. I know the only way to set speed on a c model is with the calibrations. But the a s & b s actualy told you to mark a 100 foot course on fairly level ground, we always got it moving in full forward before we started timing the 100 foot. A 953, 963, 973 should do the 100 ft in 11 seconds I wouldn't think a c would be much different Might be something to try to see how slow it is.
Even with the same measured resistance values in Steps 2 & 3 you could have one wire or the other shorted to ground somewhere between the sensor and the ECM. This is where your test light comes in. Unplug the harness at both the sensor and the ECM end. Use a 3A/5A fused test light supplied from batt+ and touch it to E902 and E903 in turn, it doesn't matter from which end. What happens.? Did you ever find CONN !4 on the machine.? Hint: It's not where you might think, and this ties in with what @1466IH said earlier regarding the harness from the speed sensors going PAST the ECM and not connected to it. In fact those wires go a LONG WAY past it, right to the front of the machine, then join another harness coming backwards to the rear of the machine. #27 is the location of the 12-pin CONN 14 which also carries the wires for the fuel level and hyd oil temp senders.
Tried the test light truck this morning and light does not light up at all so wires aren’t going to ground somewhere also while unhooked from ecm and sensor I put 12v through each wire and tested on other end and current passed through fine so I’m assuming no breaks or short to ground anywhere in the harness also found connection 4 cleaned it and no change it looked good no dirt or corrosion in it anywhere
Also swapped track speed sensor with engine rpm sensor and verified that sensor is working proper got good rpm reading using a track speed sensor gonna try the spoon idea now that Pittsburg cat man suggested wondering if I’m just not reaching enough speed to get a reading I read somewhere at low speed below level 3 that reading could be inaccurate and level three is where I stop gaining speed entirely
How would that explain why you get a reading from one side and not from the other when you select basically the same speed setting for both sides.?
That I am not sure of the reading I got on the left was very sporadic at best and since then I’ve tried several more times and getting nothing now from left or right it’s steady zeros all the time now starting to think I’ve got a demon in it
I sure would like to know if you are getting a ac milli volt signal at the ecm
Well was gonna resume testing with spoons today but have new code popped up while warming machine now get service code 079 0465.03 ? Active when you run machine at high idle disappear soon as you drop engine rpm to 2200 will come right back soon as resume high idle
That's for the throttle lever limit switch.
No biggie go to engine off calibrations sub 10 you can see the switch working
Ok tried spoons got reading every time forward and reverse would zero out when stopped and jump soon as machine moved that was with spoons right at ecm plug so does that mean bad ecm ? Found interesting thing the hot battery cable had been shorting out in clamp where it crossed over at bottom ** radiator bad enough burnt cable half into so wondering if that could have effected ecm
I wouldn’t condemn the Ecm just yet I would check the wiring to monitor first
Can you post the software number that is in the ECM? Submode 13.
I've seen that cable shorted before It's the jumper between the batteries
Yes it’s 237-7350-00 that’s what it shows in sub mode 13
237-7350-00
Ok. That's the latest S/W.
I have visually inspected wire harness to the dash it looks great as far as I see no bare wires nothing to suggest damage at least visually anyway is there a way too test the ECM
Check the connectors make sure pins are all the way in
They look good I’m really starting to wonder if just not moving fast enough to show speed seen in book that it will display 00 if moving below level 3 and I’d say I’m definitely below or right at it it’s pretty much walking pace
You could try adjusting the sensors in a little at a time. As noted above though, go easy as the gear has a fair bit of wobble without the axle installed.
Lets try the moving the throttle to about 3/4 throttle so it is underspeed
Another thought on the sync valve (taps for drive pressure are on top) there are two stems sticking on front side. They are tow valves they have about a 3/4 nut on them and a Allen drive loosen the nut and make sure they are in the whole way don’t get carried away they just go in till they bottom if you loosen the nut and it doesn’t turn in your good
Ok will try that in bit I did gps it and it’s only going 2mph full out
Is it possible mine has no tow valve I don’t see them anywhere on the sinc valve ?
Yes it possible
On the power train schematic it does say "if equipped"
Yes and some of them didn’t have a two speed switch we always ask it they were digging or load and carry when we calibrated the ones without a switch
Can you check over ride pressure should be over 230 psi check brake pressure also
Checked brake pressure it’s at zero until machine moves then runs up to about 390 until machine stops . Where do I check over ride pressure at I don’t see test port on the block
Also tested the left forward left reverse right forward and right reverse pressures at high idle full speed and they all show 200psi
Look for ovr bottom left solenoid. I wish I wouldn’t have gave all my books to my helper
Do I remove this and put my own test port in to check or am I missing something there is no test port labeled ovrd just this one in picture with wires
Are the attached of any use.?
Atta boy Nige Go to sub mode 19
also check sub mode 26,27 it will prob be in kpa 19 too
In sub 19 reads reads 00000 at low idle park 0122 high idle park 2206 high idle full forward
Sub 26 shows 0084 low idle park 0104 high idle park 1530 high idle full forward speed And sub 27 0086 low idle park and 0118 high idle park and 1544 high idle forward
I think i screwed up on charge pressure I was thinking all the c s were the same but they are not check senr1834-11 Nige sent. stall test sheet need to crank charge to high side of spec even 430 would be fine
I cranked charge pressure up to 430 still no change in speed got call back from cat been waiting all week for they shed some light said that they diagnosed machine couple months ago for previous owner they went through all steps we have and found same results we have and they concluded both pumps were weak and needs both pumps replaced that was their conclusion is it common for both to go at same time would there be way test pumps for sure just seems odd to me both go same time what are y’all’s thoughts
I don't have near as much experience as either of the two that have been helping but in my experience usually if one goes they both do. If you decide to do anything with the pumps I very highly suggest following all of the hydraulic system clean up steps because whatever is going through your pumps is also going through the motors and if you do not service those along with the pumps they will push debris right through your brand new pumps. Have a machine identical to yours in the stop right now for that exact reason. They pulled pumps and had them repaired by a hydrostatic shop but they never touched the motors or any of the control system. They brought it here so we could calibrate and after it kept failing calibrations and operating horribly we called them back and got the full story
I'm not biting on both pumps being weak I guess we need to do a stall test you are going to need a 9000 pound gauge and a test line that will stand 7000 pounds you can do one side at a time and a gage on charge pressure use the stall test sheet in 2nd thing Nige sent watch what they say about holding it at full forward and full reverse and then neutral. one more thing if they just went thru this stuff and they had sis why wasn't the charge around 430 ??
I was just thinking lets do the calibrations again when you do min track speed turn it up till it's barely moving then try the rest of calibrations I was just wondering if it was turned so far down it would effect high speed?
Sounds good I will try that tomorrow and see what I find I don’t get the weak pump deal it’s got ton power when moving it will push a mountain over but just at 2mph I know someone mentioned once that at level 3 was where pumps were fully stroked and motors take over well what signals motors to take over acts like that’s the problem it’s got ton power up to level three I even sent it down steep hill thinking if pumps are weak it would gain speed on steep downhill and it don’t it holds steady at 2 mph up and down steep hill
Another side note cat also said about 3 months ago they seen same machine and diagnosed bad ecm then said lights and codes popping up so the customer said he would replace himself and I’m sure it’s not new may be refurbished has no yellow paint on it at all
Something is telling it to do what it is doing. I've been studying brake pedal being partly depressed causes motors to go to max angle witch is slow speed even if control and pumps are at max angle To get high speed pumps have to be at max angle and motors at min angle check pedal and make sure it is up the whole way maybe a little penetrating oil would help. Ecms aren't painted new or OR ,seeing how it has the latest software in it, it sounds like it was replaced
Back in post #116, you said pilot pressure at max fwd and rev was 200psi. This is about right. I have a feeling it may be just the motors that aren't destroking. I ask again, does it look like the motor adjustments have been tampered with? Whatever the answer though, we still need to be getting a reading from the speed sensors to adjust things properly.
I can’t see any signs of the motors being messed with recently anyway I’m sure the belly pans haven’t been opened on it very recent there was 4 inches of dirt mud built up on them when I dropped them so no obvious signs of recent activity there and my question on speed display I read that level 1and 2 will display 00 for speed until you reach speed above that so wonder if I’m going too slow to register speed at this point I will retest the harness again today I know sensors are good I swapped them out with the engine sensor and got good rpm reading with both so would have to be in wiring if there is problem there or ecm ! My question is I know need reading to adjust top speed for sure but got to get machine moving faster than 1.9-2 mph first so if it’s not reading speed can that cause slow speed problem
Been trying all morning get the hydraulics up to temp for stall test can’t get them climb above 62 degree C and have moticed when you apply brakes while moving right track will stop but left track continues to move will go in circles until release brake
Get yourself self some where you have room put it in stall pull it in gear and see what it does the new book says only hold for 5 seconds in full forward
Got it warmed up as book said and hooked gauges high idle with park brake applied as stated in sub 20 put gauges on charge pressure 435 right forward 0 left forward 0 right reverse 0 left reverse 0 so skipped to stall test transmission only part high file full forward charge dropped to 400 still zero on all other ports
I’m guessing should have been checking these pressures at sinc valve not on same block as charge pressure valve I hooked there and am getting readings now
Don’t push the brake when you stall it
Last two test with implement racked full forward or reverse rpm dropped little out range and implement rack forward the right reverse pressure was just 240 where all other pressures were above 300
I'm not seeing any thing too concerning with the pressures as a matter of fact seems to be doing pretty good for weak pumps! I was interested in seeing if brakes would hold under stall. It was making me wonder when it was going in circles. Did you try turning up min. speed till it just moves and back it off 1 click?
Yes didn’t move at all under stall set perfectly still and yes sir I did try setting minimum speed again and still no change
lets try changing one of the reverse solenoids with the override solenoid careful though it might screw up reverse tracking
Did that the reverse ones are new and one forward one is new so I swapped with new one and also removed brake control solenoid it was grungy cleaned it up tested it and it acts kinda sticky like sometimes doesn’t open all way but most time as good reinstalled it and still no change in speed
Failed mention also tried calibration again still fails at 17 for setting top speed
I'm going to have to thing about this for a while Every thing you check seems right even signal to motors is pretty close it's a couple pounds shy of what it should be but it should be at least be very close to min angle on motors The thing that bothers me is if it's a motor problem they would both have to have the same problem. This seems more of a control problem. because it effects both sides. Was the guy you bought it off of the first owner? Did he mention about it being slow? This is going to turn out to be something stupid like someone was trying to slow it down to save the track!
Well I bought at auction and just now found out through cat who owned it before I can’t get in contact with him to see what he knows I’m guessing when cat told him needed two pumps he just sold this was after they told him new ecm and didn’t fix problem so guessing he just cut his losses ! I agree I think it’s something I’m just missing because it has a ton of power up to 2mph will show mountain of dirt and will spin tracks easy if you Barry bucket in ground so to me it’s hard imagine pumps are weak
This is going to sound dumb but down on the motors there are sensors to read signal pressure to motors check fittings between sensors and motor for being plugged
Ok took both lines off at motor coming from sensors for signal pressure and found nothing obstructing them then went in sub 26and 27 for signal pressure in 26 pressure was at 110 high idle park and raised to 1710 full forward and 1800 full reverse In 27 it started at 105 at high idle park and raised to 1560 full forward and 1770 full reverse
Really wondering if C mark might be right if at some point someone has been tampering with adjustments on motors ? Seems to me they are 100 percent not taking over when they need to and I’m just getting the 33 percent power
There is a way to set them look in stuff Nige sent
Yes just been studying that exact thing thinking might try to do that procedure start to finish and see what results I get
Hey Cmark I got speed readings figured out just crawled under and began adjusting sensors in from what book said was right went half turn at time and at 1 1/2 turns from bull gear I’ve now getting speed reading on both tracks
That's good. Probably a bit close for comfort but should be OK for troubleshooting. You can reset them to 3 turns when you're finished.
To adjust the motors on the machine, you will need some way to monitor track speed when you are working underneath it. Do you have access to ET? You will also need ORFS blanking plugs for the two signal hoses.
Yes I have plugs but no access to ET
You will need to figure something out. Maybe a helper in the cab videoing the display while on a face time call with you underneath??
I will try that I’ve got buddy who can probably help me with that
Do this one side at a time. Disconnect the signal hose at the motor. Plug the hose. Leave the fitting at the motor open. Put a good accurate pressure gauge on the forward signal pressure tap for the side you are adjusting. Run the engine at high idle and monitor signal pressure and track speed. Move the FNR control slowly forwards. Watch the track speed and stop at the exact moment the track speed stops increasing. At this point the pump is fully upstroked. Record the signal pressure and track speed. Return the FNR to neutral. Stop the engine and reconnect the signal hose. Back off the motor adjusting locknut and adjuster a few turns. Run the engine and move the FNR until you get the same signal pressure that you recorded earlier. Your track speed should also be the same as earlier. Start to slowly turn in the adjuster. Watch the track speed closely and stop the adjustment when the track speed JUST begins to increase. At this point, the motor is beginning to destroke to give you your upper range of speed. If you overshoot on the adjustment, back it out and start again. Adjust on the rise. You may have to try a couple of times to get it right. If you get a dead band or a sudden speed increase part way through the FNR travel, try again.
Perfect thank you I will try first thing tomorrow when my help gets here and see what I get figured out
Another thought. It may help to tighten up the friction clutch on the FNR lever to give you more precise control.
Ok we have done exactly what you have directed on the left side motor and turned adjustment in both directions with no result we did gain signal pressure but no speed gain at all
So you turned in the big adjusting screw circled in red and gained signal pressure but no speed? That shouldn't happen. Signal pressure is controlled by the ECM/solenoid valves. Are all the hoses connected to the correct fittings? Something strange is going on.
Yes adjusted the big screw you had circled in red went in about three turns no speed change so backed back out to previous setting and backed off three more turns and went back in again and still no change besides he seen signal pressure rise like 75 lbs hoses all look just like picture you sent hooked in same spots but I didn’t adjust the clutch up on the direction lever so possibly vibration of machine might have moved it little it doesn’t seem loose or floppy so I didn’t touch it
That's definitely not right. Can you trace the signal hoses back from the motors? Each one should go back to a tee fitting with a 3 wire pressure sensor.
I still think it's a control problem. since from what i can see in parts brake and steering sensors are the same pull the little panel under the pedals and swap plugs with brake and i think right steer pedal and see if that makes you any speed
Yes that’s exactly how they run I’m really thinking pressure change had to be from lever moving in cab
Ok will try
Tried it and no differents just sits at 3.58 and won’t turn up
I’m my simple mind it’s something keeping motors at maximum displacement ! Because when signal line is disconnected I’m getting the exact same speed as when it’s connected and getting good signal pressure but no speed gain at all just stuck at 33 percent of speed so if signal pressure is good is it something in the motor control that is stuck ?
Rats I was hopeful we would get lucky. I still bothered by it effecting both sides if it was some thing stuck in motor both motors would have to be stuck the same
Just to see what happens I turned the maximum angle stop screw in 1 turn on the motors just to see and it gained .1 on speed so tells me the port plate is sitting at max angle all time
Yes I was holding my breath and fingers crossed while trying but no luck lol
I will throw this out there again signal pressure left motor high idle 176 in park and 2172 full forward and signal pressure right motor is 158 high idle park and 2050 in full forward is that in spec
If those figures are kPa, then they're in the ballpark. More than enough to make the motor destroke.
Yes kpa that’s what the dash displays them in I think
It really isn't that complicated. The motors get charge pressure down one of the small lines and signal pressure down the other. The charge pressure is what moves the swash plate, the signal pressure against the spring pressure shifts the control spool and the spool directs charge pressure to either side of the swashplate piston. Next question. Do you have charge pressure at the motors? You will need to tee a gauge into the line. (I have a gut feeling this might be a blue-cap issue)
Check and see if you have hoses between x1 and x2 on your pumps
Yes both of them
Ok just checking if they had updated controllers and skipped a step yours are still org ones for machine
The only other small line I see on motors is coming in the center of the motor not on the motor control ? There are signal hoses on control and a crossover line between two motors that’s all I see for small lines
I was looking at post 198 and it is not the same as the one Nige sent us for the 963 I'm positive it is a 953c
You're right. It is 953. I was looking in the wrong folder. Let me dig out the correct one.
Hi guys you are all going to great lengths to get to the bottom of the drama for the OP… and OP is doing a great job of the troubleshooting at his end. It is a showcase of the forum at its finest! It’s also very fascinating reading I have never driven or worked on a track loader, so I may be way off with this but I have just been reading through the spec brochure for this model machine to understand some more about the machine in question. I just spotted some interesting points and it leads to my question. It states that the Electronic Hydrostatic Control (EHC) automatically adjusts machine speed to give priority to the equipment hydraulic system, while the hydrostatic system uses the rest of the power available. Does both systems use the same pump and if so can the problem actually be in the hydraulic system somewhere (as it has priority) and the symptoms showing up in the hydrostatic system due to not enough flow?
Here's the 963. It's actually even simpler. The pressure to destroke the port plates comes from the drive loop. If you can confirm that the motors are seeing signal pressure by plugging a gauge into the end of the hose, then I don't see how it can be anything other than a motor problem. But two motors with the same fault? I don't like those odds.
Re my above post…. It was a stupid question, I have just re read the pdf data uploaded earlier in the thread. Seperate implement pump is shown, should have read it properly my apologies. Two seperate pumps and motors both with same fault doesn’t seem likely unless they are just worn out from natural causes, is this a possibility? What is the rpm drop limit that the ecm starts reducing travel speed? Could someone have played with parameters like this via ET? Cmark, I remember when I spoke to you about getting ET some time ago that you warned me (very rightfully so!!!) that someone can cause a lot of problems to a machine with “Dealer Level ET” if they don’t know what they are doing. If you get my drift, thinking about the old owner replacing the ecm himself. Just a thought
That’s what I thought I will put a gauge on signal hoses right at motor and confirm the reading the computer shows is accurate I keep reading that motors won’t destroke until the pumps fully stroke so I’m guessing that if signal pressure is good then that has to mean pumps are fully stroked right ? Or am I missing something ?
Yes Jaj this forum is the best I can’t say enough good things about the experts on here I owe them all big time and really appreciate their willingness to help and provide valuable information this forum has been priceless to me
Don't get discouraged from what you have said there has been a lot of part changing trying to fix the problem. As far as pumps being at max stroke I would say that it is a real good chance they are. We just need to study and think awhile ,We'll get it figured out
Ok had short hose made with fittings for gage and unhooked signal lines from motors and installed gauges on signal lines getting 300lbs pressure around 2000 kpa on both lines when full forward high idle so pressure is for sure reaching motor control just need know why they aren’t destroking when there is sufficient pressure to them to do so
The adjustment screws for rate of stroking are almost all way in is it possible that if they are screwed too far in it won’t destroke or I adjusted them out like two turns or three when we attempted to set them but is it possible that I might need back them off more or is even possible to tighten them to the point it won’t destroke? I was afraid of backing them out too far didn’t know if that was possible
This is a cross section of the motor controller from SIS. The signal pressure is in brown at the top. As you can see, it is dead headed at the controller and only moves the servo spool. You can safely remove the end of the controller to inspect the internal components. You will lose a bit of oil though.
I have a question did you change the whole over ride valve with a reverse drive valve or just the solenoid ?
If we refer back to the graph (which is actually more than technical gobbledegook) we can see that both pump and motor see the same signal pressure. The pump is designed to upstroke from 30 - 115psi, at which point you will be moving at approx 3.5kMh. The fact you can get to about this speed with the signal line to the motor blocked means the pumps seem to be working OK. From 115 - 217 psi, the motors take over by destroking. To say that the is kind of missing the point. It's not the case that the pumps somehow control the motors and the motors aren't allowed to destroke until the pumps are fully upstroked. It's just the way the system is designed, with the motors taking over at the pressure the pumps finish upstroking.
The whole valve and selenoid I swapped
Ok got ya I thought that was what it meant but wanted make sure I wasn’t missing something there
On opposite end of motor controller from the stroking adjustment there is a plug where you can put a tap for de stroke oil pressure. since we have signal pressure might be worth checking
I seen that in book was wondering same thing what is pressure there saposed to be ?
Was reading in stuff nige sent about drive motors and seen it says pressure adjustment screw limits max speed and minimum angle stop screw also limits top speed I understand the minimum angle stop screw but I see nothing in the picture above it that shows pressure screw any idea what book is talking about am I missing something
It's on the schematic, called the pressure override valve.
Look at page 73 in senr 1834-11 that should help
Ok read up on that thanks could this be problem do I need run this test ? Or no
Guess what I’m asking is if that pressure override valve was out of adjustment bad enough could it cause my problem
I'm more interested if there is pressure there. I keep wondering if someone did the motors and screwed both motors up the same way. and yes it could be out that far but on both motors i don't know. I'm thinking there has been lots of fingers in this machine The worse thing I found with hystats is people want to turn screws They don't know what it does but say lets try it and see what happens
There's no harm in removing the valves and looking for obvious problems.
Yes, and that is what I’m afraid of is maybe everything has been tampered with by someone who didn’t know what they were doing and here we are. I am going right now to put pressure gauges on those ports and see what kind of pressure I have there if any, and I will pull those valves and check them for any obvious problems and report back in a little bit with what I find
Destroke oil pressure for left motor gauge peaked at 1000 psi high idle full forward then dropped back to about 5-600 psi and holds there
Did you try it in stall at 1700 rpm like the instructions ?
Ok done test exactly as book said this time isolated motor from other by capping crossover line between then disconnected charge pressure line capped it ran hose from charge port on motor to charge pressure nipple on ecm control block warmed hydraulics in sub 20 and put test gauge on forward pressure from sync block get reading from gauge on sync block but nothing from motor control I used the port on the side of motor control just as book shows and 9000 psi gauge and no reading at all at that port the first time I checked earlier was on port on very back motor control but book picture shows the port on the side
Book says that’s actuator pressure gauge port and it reads 0 all time even in stall at 1700 rpm
I've been study that since they are telling you that's below your serial number the picture in book only shows one tap on end and one on side. I would go to the one you were in before. From what you said before about pressure dropping makes me think it's trying to work. I also have a question for Cmark do you think its possible someone didn't get pin in port plate I remember having to fuss with them to get it in the right place. and it has the port plate trapped at max angle
So you followed the procedure " Adjustment of the Pressure Override Valve for the Drive Motor", correct.? This is sending full charge pressure to the motor signal port to make the motor go full destroke all the time, whilst monitoring the destroke pressure. You have basically confirmed what the previous tests showed that the actuator piston isn't getting pressure at the large end. It's possible the motors have been incorrectly assembled, who knows? I think at this stage I would be looking at removing the caps from both ends of the actuator and seeing is the actuator piston is physically capable of being moved. Pulling a vacuum on the tank would make this a lot more pleasant.
Yes cmark that’s exactly what I did adjustment of the pressure override valve ! Just as book showed I even ran adjustment screw in two turns which book says would turn pressure up 3000 lbs and still no reading on gauge but not sure if gauge is in the right port I used same port on side that picture in book showed I can get reading on the port on the end of motor control as stated earlier but picture in book shows that as wrong port ? That’s what my next move was thinking I’d pull whole block off the end of control and have look see what I might find might even put gauge back on the port at the end and see if anything changed there after adjustment as Pittsburg cat suggested ! Is it possible book picture is wrong and I’m putting gauge in wrong port ?
I was just thinking, If you pull the bottom off with the over ride valve. If the spool isn't near the bottom it's probably not in port plate right But I can't tell you if you are going to get oil soaked taking it off
Well pulled both ends off and looking at them can’t see anything obvious but what do I know first time looking at this seals and brings look good I can push the actuator back to make destrok but it’s pretty stiff definitely doesn’t move easy but does move
O rings
Yes they are pretty stiff good bit of pressure on the port plate to seal it are all the holes in end caps lined up with holes on main body?
Yes they are
I haven't Abandoned you I'm in thinking mode stand by
And I haven't abandoned you either. I'm in PNG. Stand by.
Ok guys I went back together with left drive motor after cleaning everything good and replaced O rings where needed and turned override pressure adjustment in about three turns since wasn’t getting any pressure reading before thought I’d try and fired it up and the left motor destroked getting lot of speed now on left side actually more than should have lol I’m gonna hook gauge back to it and see if get pressure reading if so I will set the valve as book says and then adjust the rate of stroking screw because I’m sure it way off now right motor is still the same so figure I will do same thing to it that I done to left and see what happens
Now we’re getting somewhere when I took the back cap off the drive motor control on the right motor and pull the valve out for the pressure adjustment valve. The center pin pen inside that valve is turned backwards on the left motor. It fell out in my hand and I was not sure which direction it went so I put it back as the picture showed with the pointed out towards the adjustment screw and when I pull this right apart, it is jammed in there backwards had to jar it free so it was letting it bypass all the time. No wonder I couldn’t get a pressure reading.
Hallelujah praise God put the right motor back together and it is destroking as well someone had the pressure relief valves assembled wrong didn’t catch it first time I inspected them because the cap end was all that came out and it was stupid on my part for not getting pliers and trying to pull center out but was obvious when I pulled them apart this time and seen the center pin in backwards now what step do I do first in resetting these motors do I start with pressure relief setting then set rate of stroke ?
I think I would put adj back and try it
Well great news I adjusted back where it was to begin with and had to adjust couple times but all is working great got perfect top speed and smooth transition between speeds I really appreciate y’all’s help wish I could take yall for steak dinner
Glad to hear!
Well done. Hats off to your perseverance. Don't forget to back your speed sensors out to 3 turns.
Yes will do can’t thank you guys enough thanks for sticking with me it’s been rough couple weeks driving me half crazy trying to find problem but definitely know my machine a whole lot better than I did before thanks again I really appreciate you guys !!
Fantastic morning read.....right from the first post, Glad you stuck with it Sbird, you must feel like superman now!
Yes pretty great feeling having machine working for sure ! Give all the credit to these fine gentlemen on here for their vast knowledge and willingness to help couldn’t have done without them !!
I thought I kind of knew how these hydrostats operated but after following along this thread I have definitely learned a lot more about the theory of them. There are a lot of times when I have to read and reread the theory of operations sections several times because of how complex some systems are and the way things are written by enginerds but these guys did an excellent job of describing things in simpler terms.
I wouldn't call them all enginerds I knew the one that had a lot to do with the a models. He was a good guy he could tell you how it worked and why it worked. He also told me lots of things about the a's that weren't in any books, his only thing was if he didn't think you had any idea about the hystat he figured it was a waste of his time talking to you. I had a service manager one time that spent all day trying to call him his secretary told him all day he wasn't there. By the time I came in on second shift they were pretty cranky they told me to try and call him. Hinting I wouldn't have any better luck than them trying to get in touch with him. I called and got his secretary, she said she would let him know. before I got the phone hung up he called back. It really torqued the service manager and I was loving it