Gradall 534B (9020-7317) Service Manual User Manual
Page 119

HYDRAULIC CIRCUITS
Circuit
GPM
Pump Relief
Circuit Relief
Valve psi
Valve psi
Sway
31.5
3000
Tilt
31.5
300
3250
Crowd (In-Out)
31.5
3000
Lift
31.5
3000
Auxiliary
31.5
3000
Rear Drive
31.5
3000
3000 to 3200
Steering
0-16 (on demand)
3000
2000
Pilot
2 to 6
450
GRADALL
LOED MATERIAL HANDLER 534B
HOW TO TEST HYDRAULIC MOTORS
TESTING AND ADJUSTING
HOW TO TEST HYDRAULIC
CYLINDER EFFICIENCY
(By-Pass Test)
One of the easiest tests is to observe the amount of
oil being forced past the piston rings inside of the
cylinder. The amount of oil which flows indicates
the condition of the cylinder.
Oil flowing from open cylinder port indicates
worn piston rings, or worn “O” ring between
the piston and the cylinder rod.
Leakage indicates leaking head to barrel seal.
Leakage indicates loose or worn rod packing.
Set fork on the ground.
Disconnect the hose at the rod end of the cylinder.
Plug or cap this hose.
Actuate control to extend cylinder.
Observe the oil by-pass coming from the cylinder
port. (See A, B & C)
HOW TO TEST HYDRAULIC MOTORS
(Always check pump and circuit relief
valves before checking motors)
We recommend that hydraulic motors be placed on
a test stand to evaluate their efficiency.
1.
2.
3.
4.
A.
B.
C.
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