20 - 6
Priority Valve - Standby Pressure Testing
1
Disconnect hose
A
and install a 0 - 40 bar (0 - 580
lbf/in
2
) pressure test gauge into the valve port. Position
the open end of hose
A
into a clean container in order
to collect any oil drainage.
2
Disconnect hose
B
from load sensing port adaptor
C
and blank off.
3
Set the steering to neutral, i.e. do not turn the steering
wheel, and start the engine. Gradually increase the
engine speed to 1000 rev/min while checking the
maximum pressure gauge reading which should be 5.9
to 8.7 bar (86 to 126 lbf/in
2
)
If the pressure is outside the limits try cleaning the priority
valve, refer to
Priority Valve - Cleaning
.
If cleaning the valve does not rectify, check the hydraulic
pump flow rate, refer to Section E
Main Pump - Flow and
Pressure Testing
.
If the hydraulic pump flow and pressure tests are
satisfactory, then the priority valve must be renewed.
Section H
9803/3280
Section H
20 - 6
Issue 1
Service Procedures
A
B
C
