Super major hyd.

Problem 2 Faulty ram seals, faulty "O" rings on ram cylinder, faulty check valve, faulty ram cylinder safety valve, faulty control valve.
Simple test: Raise lift, pull out auxillary service button. If the lift arms stay up, the fault is in the control valve or check valve area. If the lift still drops the fault is "O" rings or piston seal.
regards
Brian

Hmm,,,, this can be a tough one. Hopefully Brian, Stephen and others can join in here and share some ideas for trouble shooting. Concerning the first tractor...IF your fluid level is topped off correctly and the rearend/hydraulic fluid is of correct type, I'm wondering if the intake screen at the bottom of the sump is fouled. Also, something that comes to mind on both of your Super Majors is that the pumps may worn really bad and simply need to be replaced with a good used pump. Do you have hydraulic test guage equipment in order to give us some readings on pressure with out load, with load and at low and full lift height?

Chime in guys.... does this sound like a pump problem or a pressure relief valve problem?

Roy, have you renewed the hydraulic piston O-ring on the second Super Major that leaks down at low RPM?