580C low hydraulic pressure

[dwloop]

Actually, I found the hydraulic stall test in my B service manual tonight, page 4011-56, right at the end of the hydraulic test section. For power shuttle models of the B the stall test at 125'F oil temp should be 1900 RPM at full throttle, that is from 2250 RPM no load. Leads me to ask TheOldMan, I know you held the curl at stop several times but did you feel the pump line to see if the oil was warm? I bet cold oil viscosity would throw this off quite a bit... Just an idea.

BTW, I am not trying to distract from your thread, but recently after some engine work I was warming mine up like this to check the radiator and leaks. When stalling the hydraulics in the cold garage it would pull down to 1500RPM or so. I am hoping that was because it was about 30'F at that time!! After warming the engine and checking that, the hydraulic oil was still not very warm.

Dave

 

[alrman]

Actually, I found the hydraulic stall test in my B service manual tonight,

This again is for a 580B - sorry TheOldMan
I also looked harder & found specs different to yours dwloop.....
These pics are of 2 x pages
States 1900rpm for dry clutch & 2100rpm for convertor

 

[TheOldMan]

I'm gonna change fuel filters this AM and pull the power beyond fitting to see if the o rings are good. I'm really apprehensive about the shuttle stall test, I'll have to put the machine up against a tree to do it, don't trust those brakes! I'll pay a little more attention to temp of return oil line, I'm in Florida, and it's shirt sleeve weather, so the oil shouldn't have been that cold. Looking at the parts manual, there's a secondary relief valve in the loader control. I'm assuming that the primary relief is for overall hydro pressure, and secondary is for loader pressure. Is that correct?

 

[TheOldMan]

Something else just occured to me regarding the fuel thing. The two arms on the side of the injection pump that are operated via the throttle arm sping (p/n G49621-item 27 pg 57 of parts manual) are tied together with a piece of wire. The spring is there, but it was misplaced. I corrected the placement, but I didn"t take the wire off. What is the function of this spring? I'll remove the wire today and see if there's any diffeence.

 

[TheOldMan]

OK - just changed the fuel filters and took the wire off the injector pump arm. Didn't make a bit of difference. However, discovered the foot throttle must have enough wear in it that it doesn't two block the pump, but the hand throttle does. The tach bounces a little, but I'd say I'm well in range of 2250 - 2350 no load, and it drops 200 - 250 during the hydro stall test. Pressure still never goes over 2050. Pulled the power beyond fitting, and sure enough there was no oring. Installed one out of a handy dandy kit I got at Harbor Freight - no change. Might be the wrong o ring. I'll order the right one when I get this sorted out. I think I'm going to have to make a decision between pulling the loader vavle and disassembling the primary relief or changing the pump. Right now, I'm leaning towards the pump. Sorry airman, we put the cover back on the front of the tractror to add some home made counter balance. I'm going to have to remove it to paint and/or change the pump, I'll post pix then, but as far as I can tell, the outside looks just like the Cessna in the p/m. I didn't have any luck removing the pump to put a fan belt on, but guess I'll have to try again.

 

[TheOldMan]

I don't mean to hog this thread, but I keep comming up with unknowns. I went back to the parts manual, and the power beyond adapter shows two different o ring seal arrangemens. Pg 311. One is oring small, used on fittings w/o back up ring, and the other oring small used on fittings with b/u ring. How do I tell which one I need? When I removed the power beyond fitting, there was no oring there at all.

 

[dwloop]

TheOldMan, its your thread!! I guess I was the one elbowing in.... I'll not do it again though...

Good to see your RPM under stall is where it is.

Dave

 

[TheOldMan]

Hey Dave - I hope you don't think I was berating you from joining in. That certainly was not my intention. I need all the help I can get, and You always have something
relevant to add. I never considered you elbowing in. I was just afraid I was loading so many questions on this thread that the guys would get disgusted with me.

 

[dwloop]

TheOldMan, I didn't think that at all. What I meant was I think I was confusing the topic earlier by stating settings out of the service manual for a different model.

Let us know what you find with that pump. If you do a Google search for "Case 580C Sauer Danfoss pump", you will find several aftermarket dealers selling Danfoss replacements. That may be how your current pump got there. I had read somewhere that some of the replacement pumps wear better due having steel bodies instead of aluminum, I am curious if that is true.

I don't believe you can ask too many questions... Some forums I belong to get frustrated at those that don't use the search function first and ask a repetitive subject, I don't see that happen here that often.

Dave

 

[alrman]

TheOldMan, the oring gone at the power beyond will make a big difference to your BH digging power. Have you tried to dig with it since you replaced it?
It would be a good idea to return the main relief screw to where it was, just in case the low pressure problem is in the valve & it does correct itself & cause pump to fail.
The cycle time for the loader lift (fully loaded) is 4.5 seconds to maximux lift - how is it for speed?
- if the BH power has improoved (power beyond fixed) & cycle time is reasonable - I would not worry about the relief pressure, if being used around the 'farm'.

If the pump is sad, the problem will show itself, as you use the machine - let it develop.... that's what I would do if it were mine.

 

[melben]

If your pump is that bad it would not raise off the floor with hot oil with material in the bucket at idle. It would raise at idle with cold oil probably but as the temp of the oil increased the system will get increasingky more sluggish. As alrman said, a flo test is in order.

alrman, did you get my pm on the 1155 issue? I was not sure it sent properly but it shows up in my sents. mel

 

[TheOldMan]

I was able to borrow a flow meter from the hydraulic shop that rblt my cylinders. I guess the good news is, that the pump is good. Actually pumps a little more volume than the book calls for. With the load valve open, hot oil, 2000 rpm flow meter reads 25gpm. @2000 rpm with the load valve closed to get 2000 psi, flo measures 23 gpm.
Next is main relief. With the control valve hose re-attached to inlet tee, bucket rollback all the way over, full throttle, flo valve indicates about 28gpm. As you load with the
meter valve, one time it dumped at 1200psi, 2 or 3 times it didn't dump at all, then dumped at 1800psi. Didn't get a chance to read flow meter here. Backed the relief adjustment way back out, and ran again. Full throttle, 28gpm slowly loaded w/valve, started to drop a little quicker @ 25gpm. However, even when loading to get 2300 rpm where the valve is supposed to dump, it never went to 0, only down to about 7gpm, but this wasn't a dump, rather a continual even drop as I closed the valve. Didn't want to go any futher, didn't want to block the pump completely. This not what the test procedure outlines, maybe I'd better pull this valve apart and see if there's something amiss. What do you think? I haven't run any of the loader or backhoe tests yet. Do you think they would be valid with this valve acting up?

 

[tloft]

"TheOldMan" just a quick note to say that I subscribed to this thread from the very beginning, and was never disappointed by a single reply ... the fact that you have done your homework relentlessly is apparent, and stands as a reminder to all, how to get to "Know Your Hoe"
... and what a wealth of information - this thread will be referenced many times - Thanks.

 

[TheOldMan]

I really appreciate that tloft. Of I have contributed one small thing that will help someone else, itis small payment for the vast amount of knowledge and help I have received from the guys that frequent the forum and are so free with thier advice. I canno thank them enough

 

[alrman]

Assuming you have the Parker loader control valve - the needle/poppet & seat (#6 & #11) are replacable. Most times you could pull them apart & see nothing wrong with the valve except a wear groove where these make contact. Often could not get correct pressure unless they were replaced.

 

[TheOldMan]

Thanks for the tip airman. Gonna try to complete the tests tomorrow that require the flow meter, have to take it back Monday. I wonder if a hand pump off a body shop type power tool would work to test the secondary relief valves?

 

[TheOldMan]

I completed the flow tests yesterday, and could not get the bh bucket ckt pressure up to 1000psi even with the flow completely blocked. Pulled one line off the cylinder to check piston bypass, and had to plug the line before I could check it, the spool was bypassing so bad. Pressure washed everything in the valve area, but could not get it clean enough to satisfy me, so we pulled the plate and both valve groups. Learned a great lesson - READ THE SVC MANUAL FIRST. Anyway eveything is setting on the floor so will go from there. I'm open to all suggestions on refurbishing the spools and check/reliefs. I did buy a hand pump off ebay I think will work to set the reliefs.

 

[dwloop]

TheOldMan, were you ever able to get your main relief pressure up to spec?

Dave

 

[TheOldMan]

No - I think there's something wrong internally. When I get the bh valve bank back in, the loader valve is next.