Section 4 • Repair Procedures
4 - 32
GR-20J • GR-26J
Part No. 227656
September 2016
7-2
Valve Adjustments -
Function Manifold
How to Adjust the System Relief
Valve
Note: Be sure that the hydraulic oil level is at the
FULL
mark on the hydraulic tank.
1 Block the wheels at the steer end of the
machine.
2 Open the turntable cover at the hydraulic power
unit side of the machine.
3 Remove the fasteners securing the function
manifold to the hydraulic tank. Set the fasteners
to the side.
4 Loosen the clamp securing the hydraulic power
unit to the hydraulic tank. Do not remove the
clamp.
5 Remove the clamp securing the hydraulic
power unit to the chassis. Set the clamp to the
side.
6 Rotate the function manifold and locate the
system relief valve on the function manifold
(schematic item F).
7 Connect a 0 to 2500 psi / 0 to 175 bar
pressure gauge to the test port on the hydraulic
hose reel.
a
system relief valve
8 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.
Note: Rotate the red Emergency Stop button at
platform control one quarter turn in a clockwise
direction to restore the power supply. The red
Emergency Stop button returns automatically to
the out, or on position.
9 At the ground controls, press and hold the
function enable button.
FUNCTION MANIFOLD
a
