23 - 3
Loader Valve - Pressure Testing
Hydraulic Speed Control (HSC)
The following procedure can be used to establish if the
hydraulic speed control facility is working correctly.
Make sure that the hydraulic oil is at working temperature,
i.e. 50°C (122°F).
Lower the backhoe bucket and loader shovel to rest on the
ground; stop the engine; operate the control levers to vent
residual hydraulic pressure.
1
Connect a 0 - 400 bar (0 - 6000 lbf/in
2
) pressure gauge
to pressure test connector
A
.
2
With the engine running at 1500 revs/min, slowly
operate arms raise, the pressure should be
approximately 138 bar (2000 lbf/in
2
).
3
Make sure that the HSC rocker switch (mounted on the
console) is in the OFF position. Raise the arms slowly,
select the rocker switch to ON, the arms should raise
quicker.
4
Make sure that the HSC rocker switch (mounted on the
console) is in the OFF position. Raise the arms slowly,
press the button on the loader control knob, the arms
should raise quicker.
5
If the loader arms fail to respond, then check the HSC
hydraulic and electrical circuits for any faults.
Section E
9803/3280
Section E
23 - 3
Issue 1
Service Procedures
A
352710
