3-28
GTH-1256
Part No. 1272856
September 2016
Section 3 • Repair Procedures
HYDRAULIC PUMPS
How to Prime the Boom and
Steering Function Pump
1 Connect a 0 to 870 psi / 0 to 60 bar pressure
gauge to port TP5.
2 Open the hydraulic tank ball valve.
3 Start the engine, allow the engine to run at
low idle for 5 seconds and then shut off the
engine. Wait 15 seconds, then start the engine
again. Allow the engine to run at low idle for 10
seconds and then shut off the engine.
4 Start and shut off the engine again; do not
accelerate and wait for the pressure gauge to
read a pressure of approx. 290 psi / 20 bar.
When the value becomes stable, the pump is
fi
lled.
5 With the engine running, move the joystick
slowly to verify that the movements are
performed correctly.
6 Shut off the engine and inspect for oil leaks.
How to Adjust the Boom
and Steering Function Pump
Standby Pressure
1 Connect a 0 to 1450 psi / 0 to 100 bar pressure
gauge to port TP1 (pump stand-by pressure
test port).
2 Start the engine and allow the engine to run at
low idle.
Result: the pressure gauge reads 290 psi / 20
bar. The pump is good. Proceed to step 5.
Pressure is not within speci
fi
cation.
The pressure setting needs to be adjusted.
Proceed to step 3.
3 Loosen the set screw for the standby pressure
adjustment screw.
4 Adjust the function pump standby pressure.
Turn the adjustment screw clockwise to
increase the pressure or counterclockwise to
decrease the pressure. Tighten the set screw.
5 Turn the engine off and remove the pressure
gauge.
