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IMPORTANT: Always check leakage of lift cylinder seals before you test lift circuit
loader valve spool leakage.
18.2. LEAKAGE TEST FOR LIFT CYLINDER SEALS (Open Center Systems)
NOTE: Clean all parts thoroughly before disassembling any fittings. Cycle or operate the hydraulic system till
the control valve is warm to the touch.
18.2.1. Install pressure gauges in the lift cylinder rod and base end circuit.
18.2.2. With no load in bucket raise loader to full height and then hold pressure on unit for a few seconds. Read
Base end pressure it should equal tractor hydraulic system pressure. Leave unit raised for a 5 to 10 minutes and
then read rod end pressure. Rod end pressure should read zero. If pressure starts to increase in rod end and or
base end of cylinder. Lower loader and repair or replace damaged lift cylinder. If rod end pressure does not
increase no cylinder repair is required. This test can also be done with some load in bucket and with the loader
only raised slightly off of ground. This will increase the pressure in the cylinder and check the seals at a higher
pressure.
NOTE: Make sure that the pressure in the rod end circuit is zero or very low when starting this test.
OPTIONAL WAY TO CHECK LIFT CYLINDER SEAL LEAKAGE ON OPEN CENTER
SYSTEMS. (FOLLOW THESE INSTRUCTIONS IF CHECKING A CLOSED CENTER OR
LOAD SENSE SYSTEM)
18.2.3. Remove lift cylinder rod end hose.
Install tee fitting with a high pressure ball
valve and drain hose assembled to the
rod end of the lift cylinder circuit. Insert
end of drain hose into a drain pan.
Tee Fitting
High Pressure Ball Valve
Drain Hose
Lift Cylinder Rod End Hose
Install pressure gauge in
the
base and rod end of
Lift cylinder
35 Series 4WD, Model - 3535 & 4035 Loader June’08
