Valve Adjustments - Hydraulic Power Unit - Genie TZ-34/20 Service Manual

Section 4 • Repair Procedures
HYDRAULIC POWER UNIT
5-2
Valve Adjustments -
Hydraulic Power Unit
How to Adjust the System
Relief Valve
1 Connect a 0 to 5000 psi / 0 to 350 bar pressure
gauge to the test port on the hydraulic power
unit (schematic item A).
2 Turn the key switch to ground controls and
pull out the red Emergency Stop button to the
on position at both the ground and platform
controls.
3 Fully raise the primary boom.
4 Press and hold the platform up function enable
button and press and hold the primary boom
up/down button and observe the pressure
reading on the pressure gauge. Turn the
machine off.
5 Hold the relief valve adjusting screw and loosen
the lock nut (schematic item E).
6 Adjust the relief valve screw. Turn it clockwise
to increase the pressure or counterclockwise
to decrease the pressure. Refer to Section 2,
Specifi cations.
Tip-over hazard. Do not adjust the
relief valve higher than specifi ed.
7 Hold the relief valve screw and securely tighten
the lock nut. Be sure the relief valve screw does
not turn.
4 - 26
8 Repeat step 4 to confi rm the relief valve
pressure setting.
9 Bleed the hydraulic system by raising the
platform to full height. If the pump cavitates or
platform fails to reach full height, add hydraulic
oil until the pump is functioning correctly. Do not
overfi ll the hydraulic tank.
Genie TZ-34/20
January 2016
Component damage hazard.
Do not continue to operate the
machine if the hydraulic pump is
cavitating.
Part No. 825934