August 2018
Part No. 57.4400.9220GT
GTH-2506 GTH-3007
4-33
Section 4 • Repair Procedures
MANIFOLD
How to Test the Fork Tilt Relief
Valves
1 Connect a 0 to 5000 psi / 0 to 350 bar pressure
gauge to port TP1 on the function manifold
(boom and steering functions hydraulic test
port).
2 Start the engine.
3 Increase the engine speed to maximum rpm.
4 Fully retract the boom without releasing the
joystick.
5 Act on the pressure relief valve "
d
" until the
pressure gauge connected to port TP1, reads
310 bar.
6 Tilt the forks up or down.
Result: the pressure gauge reads 4350 psi /
300 bar. The pressure setting is correct.
Pressure is not within specification.
Adjust the fork tilt relief valve "
b
" located on the
Function Manifold.
7 Tilt the forks in the opposite direction as before.
Result: the pressure gauge reads 4350 psi /
300 bar. The pressure setting is correct.
Pressure is not within specification.
Adjust the fork tilt relief valve "
c
" located on the
Function Manifold.
b
c
d
8 Act on the pressure relief valve "c", until the
pressure gauge connected to port TP1, reads
280 bar.
9 Turn the machine off. Remove the pressure
gauge from the test port.
