641 lift not working

[htrdsx]

Is there anyway to bench test the hydraulic pump after a rebuild? Having problems figuring out whether it's the pump or the lift cover. Adjusted everything according to the manual. Sometimes the arms will drift slowly up when control is in lower position. It's got me stumped..

Thanks

 

[Soundguy]

pump just pushes a known volume of oil.. if it makes volume, and when oposing the flow, there is pressure.. rule out the pump... and go to the control valve.

The unloader valves are known sticky points on those machines.

In other words. if at ANY point the pump works normal to lift a load ( when hot ), then it's not the pump..