Gradall 534B (9020-7317) Service Manual - Manual (Page 125)

TO TEST AND ADJUST
DRIVE CIRCUIT RELIEF VALVES
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
NOTE: Park Materials Handler on level ground
with the forks on ground. Chock the wheels before
performing this test. Use caution while letting the
brake pedal out once pedal is released far
enough, the front wheels will engage and attempt to
drive the unit.
GRADALL
LOED MATERIALS HANDLER
534B
TESTING AND ADJUSTING
Remove lock wire from Rear Drive Main Relief
Valve.
Install pressure gage in test port (1st, inboard
section) of the tandem pump tube.
Start engine and loosen lock nut and
“bottom lightly” and back off 1/2 turn.
Tighten lock nut after adjustment
Place transmission in forward position and 2nd
gear.
Hold inching/service brake completely down
and set Mico Brake Lever.
Slowly release service brake pedal, metering oil
to rear drives.
Observe gage reading. The circuit relief in the
Forward/Reverse Control Valve should open
between 3000 and 3200 psi.
Adjust reseal or replace relief valve as
necessary. The forward circuit relief valve is
located closest to the inside of the machine
within the Forward/Reverse Control Valve.
REPEAT THE ABOVE STEPS WITH
TRANSMISSION IN REVERSE. The reverse
relief valve is toward the outside of the machine
within the Forward/Reverse Control Valve.
After completing these checks, lower the main
drive relief valve to 3000 psi, while stalled in
forward or reverse. Tighten lock nut.
Turn engine off and wire Rear Drive Main
Relief Valve.
Remove Test gage and recap test port.
5