Genie GR-12 Service Manual page 77

November 2005
REV A
How to Adjust the
Platform Lift Relief Valve
Be sure that the hydraulic oil level
is at the
tank.
1 Locate the system relief valve on the function
manifold (item I).
a
b
a test port
b system relief valve
c lift relief valve
2 Connect a 0 to 5000 psi / 0 to 350 bar
pressure gauge to the test port on the function
manifold (schematic item A).
3 Chock both sides of the wheels at the steer end
of the machine.
4 Remove the platform controls from the platform.
Perform this test from the ground
with the platform controls. Do not
stand in the platform.
Part No. 84700
mark on the hydraulic
FULL
GR-12 • GR-15 • GR-20
5 Turn the key switch to platform control and pull
out the red Emergency Stop button to the on
position at both the ground and platform
controls.
6 Press and hold the function enable switch.
7 Move and hold the joystick fully in either
direction while observing the pressure reading
on the pressure gauge. Note the pressure.
Refer to Section 2, Specifications.
8 Turn the machine off. Hold the system relief
valve with a wrench and remove the cap
(hydraulic schematic item I).
9 Adjust the internal hex socket. Turn it clockwise
to increase the pressure or counterclockwise to
c
decrease the pressure.
Tip-over hazard. Failure to adjust
the relief valves to specification
could result in the machine tipping
over, causing death or serious
injury. Do not adjust the relief
valve pressures higher than
specifications.
10 Install the relief valve cap.
11 Repeat steps 4 through 7 to confirm the relief
valve pressure.
12 Place maximum rated load into the platform.
Secure the load to the platform. Refer to
Section 2, Specifications.
13 Turn the key switch to ground control and pull
out the red Emergency Stop button to the on
position at both the ground and platform
controls.
Section 4 • Repair Procedures
FUNCTION MANIFOLD
4 - 29