Section 4 • Repair Procedures
REV A
November 2005
4 - 30
GR-12 • GR-15 • GR-20
Part No. 84700
14 Hold the lift relief valve with a wrench and
remove the cap (schematic item C).
15 While activating the platform up function, adjust
the internal hex socket clockwise, just until the
platform fully raises.
16 Fully lower the platform.
17 Add an additional 50 pounds / 22.7 kg to the
platform. Secure the additional weight.
18 Attempt to raise the platform.
Result: The power unit should not be able to lift
the platform.
Result: If the power unit lifts the platform, adjust
the internal hex socket counterclockwise until
the platform will not raise.
19 Install the relief valve cap.
20 Remove the weight from the platform.
21 Bleed the hydraulic system by raising the
platform to full height. If the pump cavitates or
the platform fails to reach full height, add
hydraulic oil until the pump is functioning
correctly. Do not overfill the hydraulic tank.
Component damage hazard. Do
not continue to operate the
machine if the hydraulic pump is
cavitating.
How to Adjust the Steer Relief
Valve
Be sure that the hydraulic oil level
is at the
FULL
mark on the hydraulic
tank.
1 Locate the steer relief valve on the function
manifold (schematic item G).
a
test port
b
steer relief valve
2 Connect a 0 to 5000 psi / 0 to 350 bar pressure
gauge to the test port (schematic item A) on the
function manifold.
3 Remove the platform controls from the platform.
Perform this test from the ground
with the platform controls. Do not
stand in the platform.
a
b
FUNCTION MANIFOLD
