Service and Repair Manual
March 2021
Hydraulic Pump
52
GS
™
-30 • 32 • 46 • 47
Part No. 1272217GT
4-1
Function Pump
The hydraulic pump is attached to the motor which
makes up the hydraulic power unit.
How to Test the Hydraulic Pump
Note: When removing a hose assembly or fitting,
the O-ring (if equipped) on the fitting and/or hose
end must be replaced. All connections must be
torqued to specification during installation. Refer to
Specifications,
Hydraulic Hose and Fitting Torque
Specifications.
Component damage hazard.
The work area and surfaces
where this procedure will be
performed must be clean and
free of debris that could get into
the hydraulic system.
1 Tag, disconnect and plug the high pressure
hydraulic hose from the hydraulic pump.
2 Connect a 0 to 5000 psi / 0 to 350 bar
pressure gauge to the high pressure port on
the pump.
3 Turn the key switch to ground control and pull
out the red Emergency Stop button to the on
position at both ground and platform controls.
4 Activate the platform up function from the
ground controls.
Result: If the pressure gauge reads 3200 psi /
221 bar, immediately stop. The pump is good.
Result: If the pressure gauge fails to reach
3200 psi / 221 bar, the pump is bad and will
need to be serviced or replaced.
Component damage hazard.
There is no relief valve in the
hydraulic pump and the pump
can be damaged if the pressure
is allowed to exceed
3200 psi / 221 bar. When testing
the pump, activate the pump in
one second intervals until
3200 psi / 221 bar is confirmed.
Do not over-pressurize the
pump.
5 Remove the pressure gauge and reconnect
the hydraulic hose. Torque to specifications.