Hi everyone. I recently purchased a Case 580 sl. Hydraulics get slow and weak within about 10 to 15 minutes of use with the loader or backhoe. I bought a gauge and did some tests and would appreciate some help as to what they mean. With the fluid warm, approx. 130 degrees(pump about the same temp). I get the following readings with a pressure gauge hooked up to the test port by the pump; Loader(with a full bucket): 1000 to 1200 psi when raising, 1400 psi when it stops-approx. 3/4 up. At a certain point it will not raise all the way. Backhoe(loaded 2' bucket) 1500 psi when raising boom(fully extended dipper) 1000 psi when stopped-partially up. I don't really know that much about hydraulics and decided to do the tests after some reading on this site. I'm thinking that the hydraulic pump is bad, but would hate to buy a new one when I don't need to. Thank you, Doug
Is the hydraulic tank full ? Sorry, I had to ask. Have you changed the hydraulic filter ? There is a screen (#18) in the loader valve that may or may not be dirty. Here is link to the online parts book page for it. https://partstore.casece.com/us/par...N¤cy=#epc::mr52163ar1098496bi4728555-18
When you load the bucket how are you doing it?
Dead head, roll the bucket back when cold. Dead head roll the bucket back when warm. Pressure should be just aobut the same. If it's different, then yes, you're onto something
Thanks for the replies. Tinkerer, Yes the tank is full. I just changed the fluid and filter. Thanks for the picture too! I kept reading about cleaning screens but could never figure out where any of them were. I think the machine has not been used much in the last few years. All the filters are marked from July 2010. Coy, I am loading the backhoe bucket and loader bucket with gravel and then raising them up and down. It starts off working great and after a while gets weaker and weaker until it gets to the point that it will only raise the backhoe a few feet off the ground and the loader maybe 7 or 8 feet. Doug
mikebramel, I assume dead head means to roll the bucket all the way and hold it? When I do it cold, I get about 2800 psi for a second or so then it drops to about 2400 psi. When warm, it's at about 2000 psi for a second, then down to about 1500 psi. The hydraulic tank temp was about 95 degrees and the pump about 115 to 120. The hydraulics were weak at this point. Doug
The way to check pressure is to roll the bucket all the way back and hold it and then take pressure reading while holding bucket back. Sense you're telling the hyd. slow down while you are working the machine it doesn't mean your pump is bad but of course it could be.
Just to clarify the main relief test procedure a little further - Just as @Coy Lancaster says in the above post, move a circuit, ie loader rollback, all the way to the stops - & test the pressure at full engine RPM. The pressure should hold, if it fluctuates - the main relief valve is suspect. Each application of pressure, should see the same pressure, If there is a difference of pressure with each application - the main relief valve is suspect, & should be replaced. Testing the pressure at low RPM should go near the specified pressure & still hold. If the pressure should move up & down with engine RPM (pressure gauge looks like a tacho...) the relief valve is stuck open. A valve that is stuck open can 99% of the time be removed & the obstacle which is holding the valve open (usually piece of oring) can be removed, the valve refitted & the machine will function normally again. The relief for 580SL is 3000 - 3100 PSI @ 2200 RPM You may indeed have a tired pump, but, I've replaced alot more valves than I have pumps.
OK, did some more tests. The pressure will vary form 400 to 1800 psi as I rev the engine, so it sounds exactly like what you described! I will try to clean the valve and see what happens. I really do appreciate the help. Doug
Pay very close attention to the diagram in the on line parts book after you disassemble the valve assembly. I had a loader valve apart once and some bonehead had previously left out a very small spring. I cannot describe the aggravation it caused for anyone that ran the front end loader.
@Doug580l there's no need to dismantle the entire valve, simply remove the main relief cartridge from the loader control valve. You should see the obstruction caught in the lower poppet porting. You may need to push in the poppet with a blunt screwdriver or pin punch, remove the culprit & refit the valve.
Good advice. I ordered a seal kit and will be taking it apart next week. Doug
That would be great if that's all it is. I'll try that this weekend. Doug
Please forgive me for not understanding, this is all new to me. I am supposed to be removing the relief valve on top of the loader control valve on the inlet section and not the main relief valve on the outlet section? If I am supposed to be removing the one on the picture that tinkerer sent, how do I get to it? It appears to be on top of the valve housing and I don't see how I can get a wrench on it. Thanks, Doug
It looks like I could get to it from the cab by removing the floor. Please let me know if this is correct. Thanks, Doug
The main relief valve (#6) is located in the outlet section, easily accessed from under the machine. The steering relief valve is the one located in the top of the inlet section.
Thanks for the quick reply alrman, I appreciate the help. So there is no reason to remove the steering relief valve? I removed the main relief valve and didn't see any blockage. It looks like there is a small screen on the bottom and it looked clear. Should I spray solvent on it and blow air through it? I didn't take it apart and I'm not sure that it comes apart. I don't see a breakdown of it like there is for the steering relief valve. I'm going to try to post a picture of it. Thanks, Doug
By all means, blow some air into those ports & see if something shows itself - Even try blowing into the loader control valve cavity as well. If there is nothing visible in those porting holes (do I see something in that picture???? not sure...) & the poppet is properly seated - then the valve has to be replaced. They are not serviceable, well not without making a real mess of them....& no parts are available for them at all.
I cleaned it up as best I could. I didn't see anything come out while blowing air into the ports and the poppet moves in and out easily. There is a slight dent in the side of the relief valve, maybe that is part of the problem. It is defiantly working better no than before. The pressure now holds at about 1750 psi while curling the bucket and close to 2000 psi for curling the backhoe bucket. It will still fluctuate when changing the engine rpm, form about 450 to 2000. From what I read, I should be getting 3000 to 3100 psi so I will be replacing the relief valve. Just a shadow or a reflection in the picture that you saw. I looked at the entire thing with a magnifying glass. Thanks, Doug
Me thinks you have problem with O rings on spools.I had a very similar problem with heaps of pressure variation with readings from 600- 1800 PSI yet the pump was pushing 3200 PSI. To fix I replaced every 0 ring and backup ring on the control bank. It's worked perfect since
Have you tried adjusting the relief valve?
That sounds like a pretty complicated job, at least for me. Sure hope the new relief valve solves it.
No I haven't. Should I? Not knowing much about it, I was worried that I make things worse. The pressure does get up close to 3000 psi for a second or so when I dead head a cylinder. Then it quickly drops and holds at between 1750 and 2000 psi. Another thing that I noticed after cleaning the relief valve is that before cleaning it, at dead head the pressure would slowly drop from about 2000 psi to 1000 psi over 5 or 6 seconds sometimes. Now it drops and holds in about a second or so.
Adjusting pressure is easily done by loosening the jam nut and turn allien screw in until pressure is correct.
If you get 3,000 PSI for a full second, then I wouldn't turn up the relief valve, you might get more trouble. That sounds like it's sticking, or operating slow. I'd replace the relief valve, or take the old one apart some more to see if anything is bent, broken, or gummed up with garbage. Nothing to lose if your alternative is to buy a new one anyway. Just mark the position of the nut and put it back the same way on assembly. Your next step would be a flow test on the pump, or replace it instead of testing.
Doug, I was a bit hesitant at the start as it was a job i'd never done before but I had no other option. 2 main things are to have a very clean work space and a good memory. ;-)
That's what I was thinking. I have the new one ordered so hopefully that ends up being the problem. I have no way of doing a flow test so I might end up having to buy a new pump. The dealer wants over $1300.00 for one. What do you think about an aftermarket one like they have on ebay for about $750 or so?
The clean work space is doable, the good memory hasn't been around for several years. If I do it, I will take lots and lots of pictures as I disassemble it.
Thanks.
You're welcome
Put the new relief valve in and it's about the same as the other one. When the fluid is still cold, it will get up to about 2800 psi. With the fluid warm, not necessarily hot these are the readings I got. Loader bucket curled. Goes to and holds at about 1500 psi. Backhoe bucket curled, goes to approx. 2000 psi and over about 10 seconds drops and then holds at about 1000 psi. What now? New pump?
That pressure dropping is funny. With the engine cold, try the backhoe bucket curled for ten seconds and shut off the engine with the bucket curl held still, then jump off and take the temps of the hydraulic pump, loader valve, and backhoe valve. That might show you the smoking gun, hopefully not literally. The pressure reacting differently makes me think the loader valve is leaking worse, but I don't know how the "power beyond" is set up to make the loader and backhoe valves work together. That is the key at this point. Unless the pump is hot and the valves are both stone cold with that test, then it's the pump, but how do you explain the pressure difference? Without doing a flow pressure test directly off the pump, we're guessing.
+1 The last sentence of Delmer's post is exactly what you should be doing or all you are doing is guessing and that cost's big buck's for no result. Isolate the pump and test. If it's good then move onto the control bank and pressure test every port. AND DON"T TOUCH ANY PRESSURE RELIEF VALVES until you now what the problem is and where.
Is the pump a gear type? If so, there's a simple way to confirm if it's any good. Dead head the pump outlet and attach a high range pressure gauge. Very briefly crank the engine (disable it from starting). If the pump is good it will immediately peg the gauge. This doesn't apply if it's a piston pump.
The best way to find out is have a tech come out and preform a flowmeter test. This will take out all guess work cause all we'er doing here is poking a finger at problem.
Just performed the test that you suggested. Pump. Temp before. 78 After 107 Loader valve. before 72 after 87 inlet valve and 77 outlet valve BH valve before 74 after 74
I'm sure you are right. I will contact the dealer and see how much it will cost. Unfortunately I am over 60 miles form the dealer so it won't be cheap. I was being cheap when I bought the machine. It was about 90 miles from the dealer and I didn't want to pay what they wanted. Paying the price now.
Yes, it is a gear pump. So, if I remove the pipe coming from the outlet side of the pump at the inlet of the loader valve and cap it off, then I take the pressure reading at the test port?
Wait until you install the new relief valve you have coming. You already said there was difference after you reinstalled it. When you have it out, crank the engine a couple of revolutions so anything lodged in the passage-way can be flushed out. Have you changed the hydraulic oil filter and inspected the pressure relief valve ? It is in the hydraulic tank. I would advise you to do that while waiting for the new relief valve.
I did put the new relief valve in today and it is about the same as the old one. I'll take it off and crank the engine a little as you suggested. I did change the hydraulic fluid and filter. How do i get to the relief valve in the tank? I looked at the parts book and don't see a relief valve being in the tank.
I forgot you had the new valve in. I hate being old !! The relief valve (#17) for the filter is the device that the U shaped wire retainer presses against. It will open when the hydraulic filter plugs, therefore preventing the pump from being starved for oil. Is there any noise coming from the pump coupler ? Can you see any oil leakage at the pump input shaft ? There is a remote chance that the suction hose is collapsing internally. A flow test would show it.
Lol, yes, being old sucks. I have notes laying around all over the place to help remind of things that I shouldn't need reminding of. And half of them I don't even remember writing. Any chance you could give me a link for the picture of the relief valve that you're talking about? I can't seem to figure out where it is. I can't see any leaks at the pump input shaft. I'm not sure about any noise coming from the coupler. I'll probably have to try and check that when I have another person around. I assume that you are talking about a noise when the pump is under a load?
That confirms the loader valve is leaking worse, and the backhoe valve is fine- most likely. Could be the pump is shot? I would go to the trouble of rigging up a line back to the tank and a high pressure valve and tee with your gauge. It doesn't have to be as big diameter as the line you have, 1/2" is fine. If the outlet from the pump goes straight to the loader valve, you can disconnect it there, and all you need is the fittings to connect a tee, valve and gauge there. The outlet can go back to the loader valve. Most likely Tone's test is fine, but if your pump, starter and battery are in excellent shape, they might not be for long...
I am trying to make sure I understand the test so that I don't do any damage. I am including a picture of the test port that is on a tee between the pump outlet and the loader valve inlet. If I remove the line on the right side of the tee(the line going to the loader valve) and plug it, can I just use the test port with a high pressure gauge? Or can I just leave it as it is and use the test port with the high pressure gauge? Please for give me for being a little slow.
If you plug the line and use the test port there, that's Tone's method, disable the injection pump and crank the engine briefly/enough to see if you get 3000 PSI or not. Another way is to put a high pressure ball valve after the gauge, but before the loader valve, and with the engine idling, close it slowly until you can see if you reach 3000 PSI or not. Either method is potentially harmful or dangerous if you close it and the pressure spikes and blows a line etc. won't be back till tomorrow. Good luck.
Yes. You're dead heading the pump and seeing what pressure it's capable of producing without any way of relief. Go carefully. Just the briefest flick of the starter motor until you get a handle on what it's going to do.
I'd be unplugging the shut off solenoid if dead heading the pump or find a safer way.
I understand both ways of testing now, thanks everyone. I do have 1 more question, might be a stupid one. If I do go the route of plugging the line and testing the pressure, will the pressure leak down on its own back through the pump or will the line hold the pressure until I somehow release it?
Yes, the pressure will mostly leak off through the internal clearances in the pump.
@Doug580l hmmm, Sorry to hear the relief valve replacement didn't fix it for you. Everything you previously described had me convinced you had relief valve problems. The senario you are now describing seems to indicate it does have pump symptoms. What is the gauge read during pressure test (full rollback) & varying the RPM? Does it fluctuate as it did before? Is any there any pressure present at full RPM while all levers are in neutral? When you hold the rollback; the 4in1 (If you have it) or the lift on pressure - does any other circuit move? Have you tested the steering relief? (2050psi - 2200psi) Does the steering feel OK? This low pressure should make the steering feel heavy... The reason I ask is that there is a priority valve in the inlet section which gives flow/pressure to the steering as priority & it may not be working correctly. A flow meter is really your best & safest option at the moment.
Ya, I was hoping it was the relief valve too, but that's the way it goes. The pressure still fluctuates when varying the rpm like it did before. I don't think there is much, or any pressure present at full RPM when all levers are neutral. I didn't notice any other circuits moving when I held the rollback. Didn't check the steering relief. Not sure how. The steering feels fine, but I didn't check it with material in the bucket to weigh it down. It seems pretty light in the front end when the bucket is empty. Sounding like I need to get the a flow test. Would something like this work? https://www.amazon.com/Hedland-H601...379&sr=8-3&keywords=hydraulic+flow+meter&th=1 Or am I better off having a mechanic from the dealer come out and test it? I like spending money on tools.
Do you have the service manual for your 680 ? You really need one to fully understand the procedures and equipment needed to do the flow test. Please don't take that statement as a put down. It takes a lot of training for a technician to thoroughly learn to do the flow test procedures.That meter on Amazon isn't what you need. The pressures that your pump can develop when doing the dead head test can be quite dangerous if a line bursts. Oil injected into your skin can be life threatening. Or you could be blinded without proper eye protection. The lines in a machine that old will have weak spots where you would never expect them. I am posting a photo of your loader control valve just for reference. It shows the main relief valve and the power beyond valve.
Tinkerer, I appreciate your post. I do have a tendency to jump into things without fully understanding them. If I can't get this figured out I'll have a mechanic come out and do it. I've got several other issues with the machine too so I'll probably try to fix them and if I can't I can have the mechanic check them too as long as he's here. I do have a service manual for my 580. Just got a paper one yesterday. I had one on cd but it's pretty much unusable for me. The search feature doesn't work well and my arthritic hands can't take 20 minutes of scrolling through it trying to find what I'm looking for.
Was the 580 a mistype ? I have read that some manuals on CDs are not very good. I understand the arthritis problem you have. I have it in my back. I thank God my hands are free of arthritis. Keep posting back about your progress. Don't get discouraged. Keep asking questions. HEF has the best help possable that can be found anywhere, for anything related to the construction industry.
Doing a pressure test on just the pump will probably give you enough info to decide whether to replace the pump or not. Deadheading it like Tones and Cmark said, or using a valve like I mentioned. Tones and Cmark have way more experience than I do, so I'd trust their judgement. If your pump is not capable of more than 2,000 PSI deadheaded, then you don't really need to know the volumetric efficiency. Alrman is THE expert on these Cases, and he brought up some critical info about the priority valve that I was not aware of. Does your manual have any info on valve leakage rates? On a closed center system, testing the valves is easy, you just take the return off and measure the ounces of oil dripping per minute. If there's not a procedure in your manual, you could figure out how the steering priority valve is supposed to work, and either cap the lines to it, or measure the return oil with a hose into a bucket, then crank the engine with the injection pump off and the bucket curl held back, and see what pressure you achieve and return you get out of the loader valve. Sorry to make this seem so complicated. There's just different ways of looking at this problem. And different ways of finding out what's going on- where's the pressure and flow?
Tinkerer, thanks for this post. I was feeling kind of bad asking so many questions and not picking up on things as quickly as I would like to. I've learned a lot form reading through the forum so far. The machine is a 1997 580 Super L.
I just got a usable service manual so I'll start looking and hopefully be able to figure out how to do some of these tests. Most likely I won't be able to, lol.
So, you took the entire loader control valve assembly apart and put new o rings in everything? I was looking at it in the service manual. It looks like a lot of meticulous work(not a strength of mine). Is there an o ring kit for all of it or do I have to buy them separately for each section or component?
Hang in there Doug, you will get the help you need. Disregard my earlier posts with photos. I had my head in my ### ! I was thinking of a different machine entirely when I looked up those photos in the parts book. I wouldn't worry about resealing the control valve just yet. Although that may be the problem. Do the dead head test on the pump first , like Cmark and the others suggested. Hopefully Alrman, Coy or Melben will be back and help you some more. They are the true experts in all the Case T/L/Bs.
If you can find anything in your manual on the steering priority valve, that sounds like the next place I'd look.
Doug, Mine is a wheel tractor with a 4 spool load sense control bank and priority steering valve but the princable is still the same.Pressure bleed off can occur anywhere in the system. IMHO check and test everything in order from the pump before buying parts, even the rams if necessary.
I tried doing the dead head pressure test on the pump. I assume that I must of lost prime because I am getting no pressure readings. I have the line capped off about 3' past the pump at the test port. I used the air hose in the hydraulic tank to help get prime, but it didn't work. Should I hook up the lines again and run the machine until the hydraulics are working and then take it apart again and try not to let much fluid out? Not sure what to do. Also, is the fluid supposed to be warm for this test?
Doesn't matter about the temperature. You're only trying to get a pass/fail on the pump. If it's any good it will peg the gauge. Anything less and the pump's no good. Remove the gauge and put the hose into a bucket while you're cranking in order to bleed the air out.
No pressure for this dead head test (I don't really approve of it, maybe cause I have a flowmeter..) could be loss of prime OR could be the pump is not turning with the load it has on it. IF the pump is worn, it will possibly lose prime when the delivery hose was removed & capped. IF the drive coupling/pump shaft is worn & was somehow allowing rotation of pump during testing & allowing some pressure to occur, maybe the dead head test has finished it off, & now it has no drive at all?? I would re-connect the output hose & see if you can get pressure again. Putting air in the hydraulic tank maybe required if it has lost prime, OR while the engine is idling, crack the delivery hose fitting a turn or two to prime it. Maybe it won't work at all due to the drive coupling being stripped?? Shining a good torch down into that drive coupling area may show if the pump shaft is turning. While on this subject, check the front engine mount frame where it attaches to the engine block - are the 4 mounting bolts still in place & tight? If the hydraulics do function, carry out the steering relief test by attaching the gauge to the same test port & turning the steering to full lock at full RPM - let me know the pressure.
Edited out useless info. I was typing when Alrman replied.
Thanks guys, I am done for today. I will try again tomorrow and let you know what happens.
Did the tests that you suggested. When I hooked the line back up the hydraulics worked immediately, as if it never lost prime. The pump shaft is moving when doing the dead head test. All 4 mounting bolts on the front engine frame are in place and tight. With the gauge on the test port by the pump and the fluid cold, at full RPM I get 1800 psi when the steering is at full lock. About 1400 psi when the fluid is warm. I got about 1550 psi with the bucket curl after the steering test, fluid warm. I disconnected the line and tried the dead head test again being careful to lose as little fluid as possible. Same result, not pressure at all. That seems weird to me, but I don't Know much. I also looked into the hydraulic tank while the engine was being cranked while dead headed thinking maybe the pressure was somehow going there, but saw nothing.
If you have a way to haul it then take it to them. That way you won't be charged a service call.
I don't have any way of getting it there. They charge $3.00 per loaded mile to move the machine, which seems reasonable. So it will cost about $400.00 round trip. Not sure what the service call will cost. I am getting to be of the mind frame of buying a new pump and if that doesn't fix it, having the dealer figure it out.
Well Doug, everything seems to be pointing to a tired hyd pump. There is not enough pressure at steering as well, + it falls as the temperature rises. I'm wondering if you tried varying the RPM while holding the steering on relief & if the gauge reacted the same as the main relief?
Sounds like frustration has set in. If you get a new pump there is a manufactures tag on the pump a lot of times you can go to a hydraulic pump rebuild shop or look it up online to fine a cheaper price.
I just did that with the steering now. It acts the same when I'm holding the steering on relief and rev the engine. It varied from about 400-500 psi to around 2000 psi.
Good advise. I kind of do that now. I'll get the part number and then do a google search. Looks like I can get a new one from around $650 to $900 depending on whether it's the 15 or 17 spline one.
You should replace the coupler also Doug. You don't want a new pump spline on an old coupler spline. Well I wouldn't.
I was wondering about that, thanks.
Not a bad idea also check your fan belt and go ahead and replace it while your're there.
Yup, I'm replacing the belt, fan shroud, radiator hoses and front motor mounts too. I don't know if I need to start a new thread or not, but I can't get the pump out. I don't have hardly any experience with it. I removed one on a case 1840 skid steer and it came out easily. I've tried using a chisel, a hammer on the front sides and a crow bar underneath it(front mounts are very loose). I decided I'd ask before I get the sledgehammer out.
Got it. I did have to just hit it harder and harder until I got enough movement to get a chisel in it.
Yeah I've had that problem before had to use a sledge hammer also.
Wanted to update everyone who was kind enough to take the time and help me. Got the new pump in and it works great! Amazing how strong it feels now, even at idle. It will now hold at 3100 psi. Now, back to the 20 other things needing repair. Thanks for all the help, it is appreciated.
With that low pressure, your hydraulic pump is junk. Don't waste money trying to rebuild it, you won't. When you replace a pump or main relief replace both. If one is bad the other isn't far behind. More in upfront cost, but it will save you a lot of down time.