Case 1175 Hydraulic Pressure

[larson9856]

I bought a Case 1175 with a loader on it, person I bought it from said the hydraulic pump was bad, there's a gauge on the loader control that was showing only 500psi. I checked the psi at both rear take off and only got 500psi, disconnected the pump and put a gauge on the output and pegged the gauge at 3500psi, obviously problem is not the pump.
can anybody point me in a likely direction of the problem?
I have repaired and Rebuilt hydraulics in my smaller tractors and dump truck, but this system is a bit more complicated.
Any guidance on this would be greatly appreciated.
THANKS

 

[used red MN]

FYI, he posted this in Tractor Talk as well. I will link that
post here. Can anyone tell him where the relief valve is
located?
Tractor Talk post

 

[jon f mn]

I also replied on tractor talk. The relief
is under the valve, so the valve has to be
removed. That requires taking the fuel tank
out which is the hardest part. You can get
whatever parts you end fm external_link
in NY, just Google them.

 

[mEl]

If you deadheaded the pump and ran it the pump is destroyed, A Positive displacement pump will not tolerate having its outlet blocked off with no place for the oil to flow, Pumps are rated in L/pm for each revolution and must be able to flow. Pressure without flow is worthless and you have proved there is no flow by blocking the pumps outlet, if the pump would have been in good condition the section would have split wide open because the oil has no place to go. You need to get someone who has a flowmeter to diagnose the system, the relief valve is located in the Dual Remote Valve under the tank and has Orings in the relief which can fail also and may have been the problem at first but you need to look at the pump now.