Excavator Valve - Precision Control (Servo)
(Machines up to serial no. 931159)
Pressure Testing
Load Sense Drain Regulator and Relief Valve
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
on the loader valve, (refer
to
Service Tools
).
2
With the engine running at 1500 revs/min, check that
the M.R.V. pressure is correct, see
Loader Valve -
Pressure Testing, Main Relief Valve.
3
With the engine running at 1500 revs/min, operate a
stabiliser service fully and at the same time note the
reading in the gauge which should be as stated in
Technical Data
.
Note:
The ram must be 'held' open or closed when reading
gauge.
4
If the pressure is incorrect, loosen locknut
D
and adjust
screw
C
. Turn the screw
C
clockwise to increase
pressure and anti-clockwise to decrease the pressure.
When the pressure is correct, tighten the locknut and
check the pressure again. Adjust as required.
23 - 10
Section E
9803/3280
Section E
23 - 10
Issue 2*
Service Procedures
A402500
A
C
D
*
