970 hydraulic pressure

[Determined]

Was out shredding bales this afternoon with the 970.
The lighter bales 1100-1300 lbs were going through fine.
As soon as I tried some greenfeed bales 1750 lbs the hydraulic driven rollers that turn the bale in the processor were turning a rotation of two then stalling.
The processor normally handles these bales without a problem until this past week when temps have been above freezing during the day, causing the snow to melt making a wet soggy mess of the outside top couple of inches of the bales.
To see if it was a hydraulic problem with the tractor or a problem with the orbit motors on the processor I backed up another tractor to it and swapped over the hydraulic lines that run the orbit motors, it was a grunt for it but they did start turning.
Tried a lighter bale after fighting with the greenfeed and it worked fine.
The other tractor has enough hydraulics but does not have 1000 RPM PTO so I can not just switch it over.
So my question is What PSI should a good pump on a 970 put out?
I will do some tests in the morning and if needed I have a 1070 parts machine with a replacement pump on it?
Oil is fine, filters are recent, loader, powershift and steering are working fine.
Am I missing anything else to check?

 

[1370rod]

First thing to do is to have the pump flow tested at the pump outlet. At operating oil temp a good pump will develop 2200 psi easily. If that checks OK, test pressure at
the couplers, that pressure can be set up to 21-2200 psi safely but requires valve removal. If valve has to be removed I would highly recommend servicing the entire valve
The check valves in there can cause a loss of pressure also. The best thing is to have the valve bench tested before installation, Rod.

 

[mEl]

(quoted from post at 09:55:21 12/03/15) First thing to do is to have the pump flow tested at the pump outlet. At operating oil temp a good pump will develop 2200 psi easily. If that checks OK, test pressure at
the couplers, that pressure can be set up to 21-2200 psi safely but requires valve removal. If valve has to be removed I would highly recommend servicing the entire valve
The check valves in there can cause a loss of pressure also. The best thing is to have the valve bench tested before installation, Rod.

Rod is right about the pump testing at 2200 PSI. I would be more concerned about the flow GPM at the 2200 PSI with hot oil, a bad pump can test its rated pressure but that is worthless if it is only at a gallon per minute, I also suggest that the pump be flowed out of circuit as well, I like to see a pump within 20% or at worst 30% of its cold oil flow specs. A worn pump can produce a significant amount of heat.

Also as Rod suggested if the control valve is serviced the thermal reliefs in the RH end cap should be checked as a failure there will cause leak down on cylinders attached to that remote coupler.

In our area we have seen problems with the o ring at the top of the relief valve sleeve being completely gone causing very low pressures. The O rings and Backup ring in the sleeve bore should be replaced.

Keep us posted

 

[Determined]

Had a look at the 970 today.
Pressure at all remotes is 1900 PSI.
The John Deere that I had hooked it up to for testing is reading 2400 PSI.
As my flow meter is only good to 10 GPM I did not hook it up.
Looking at a manual it is showing the PSI spec for the relief valve on the dual remotes to be 1700-1900.
So in reality it is putting out what it is supposed to and it does work perfect with any other implement I have hooked to it.
First thought was pull the remote valve and add another .020-.025 in shims to the relief valve which if I figure right should bump it up to about 2200 PSI if everything else is in good shape.
Looking at it of course you can not quite get the relief valve plug out without removing the whole thing.
From there I an guessing at best I would have to jack up the back of the cab to give me enough room to get it out of there.
Too late to tear into it today as the cows need to be fed with it in the morning.
Hey almost sounds like a good excuse to look for another tractor and a good enough reason that I might even get away with it. Or not?

 

[1370rod]

Sounds like the tractor is doing what it should, if you added the amount of shims stated you should be right in the ballpark. Yes the back of the cab platform needs to go
up a little and it is still a pain to remove. That is the reason I mention having it bench tested before reinstalling. I have one off now and it will get pressure tested
before I install it. Rod.

 

[Determined]

Ran a few more bales through and fought with them.
Tried hooking another tractor to the hydraulics again and it did not help.
Adjusted the shredder as per manual and it got worse.
Adjusted again completely opposite of what he book calls for and it chewed through 4 bales in no time with no problems.
Glad I didn't tear into the hudraulics first, only to find out it wasn't the problem in the first place.
Thanks to all who offered info and advise.