September 2016
Part No. 1272856
GTH-1256
3-25
Section 3 • Repair Procedures
Hydraulic Pumps
6-1
Boom and Steering Function
Pump
How to Test the Boom and
Steering Function Pump
1 Connect a 0 to 5000 psi / 0 to 350 bar pressure
gauge to port TP1.
2 Start the engine.
3 Increase the engine speed to maximum rpm.
4 Activate and hold boom retract.
5 Without releasing the joystick, keep pushing
the throttle pedal.
Result: the pressure gauge reads 3770 psi /
260 bar. The pump is good.
Pressure is not within speci
fi
cation.
The pump needs to be adjusted OR the pump
or pump coupling is faulty and needs to be
serviced or replaced.
NOTICE
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
speci
fi
cation. When testing the
pump, crank the engine in one
second intervals until the correct
pressure is con
fi
rmed. Do not
over-pressurize the pump.
6 Remove the pressure gauge and install plug
onto port TP1.
