casey518
Well-Known Member
My 1986 JCB loses hydraulic pressure as the fluid reaches warmer temperatures. I am running new ISO 46. The machine has a gear pump and a relief valve that controls the loader and hoe pressure independently. When I first start the machine all functions meet spec pressure (about 3000psi on these machines) As I operate the machine for a while the fluid will heat up. I believe iv taken temp readings on the warm fluid to be around 120-140 degF. At this temperature the tested pressure is reduced to around 1800 psi in both the loader and hoe functions and the machine is noticeably weaker.
Some things I have tried:
-Replaced Hydraulic return filter
-Replaced Fluid
-Replaced suction screen in tank
-Removed and inspected relief valve (didn't see any obvious problems)
-Maxed out relief valve adjustments
I fear that the pump may have seen its day and is no longer operating efficiently. When I opened up the tank ports I did find a lot of garbage. Chewed up bits of old seals I assume. I was sad to see there was no suction screen installed. No way of knowing how long it was like that. Have I covered all the bases before a pump replacement or am I missing something? Thanks!
Some things I have tried:
-Replaced Hydraulic return filter
-Replaced Fluid
-Replaced suction screen in tank
-Removed and inspected relief valve (didn't see any obvious problems)
-Maxed out relief valve adjustments
I fear that the pump may have seen its day and is no longer operating efficiently. When I opened up the tank ports I did find a lot of garbage. Chewed up bits of old seals I assume. I was sad to see there was no suction screen installed. No way of knowing how long it was like that. Have I covered all the bases before a pump replacement or am I missing something? Thanks!