Slew Motor Pressure Relief - jcb JS300 Service Manual

1 Prepare the machine
a Operate the dipper out and lower the boom to set
the bucket on the ground.
Fig 23.
b Make the machine safe, refer to Section E,
Service Procedures.
2 Connect a 0-400 bar (0 - 6000 lb/in
and adaptor to test point TP2.
3 Initiate slew lock procedures.
a Remove the water-proof connector on the slew
lock solenoid valve.
b Press the slew lock switch which is on the right
hand console inside the cab, and confirm that the
slew lock symbol appears on the monitor.
c Start the engine, (error codes may appear for
disconnected solenoid) and operate the engine at
around 1000 rpm, then operate the slew lever
slowly. Listen to confirm that the relief sound is
heard and that the machine does not slew.
d Run the engine at minimum no-load speed and in
the E mode.
e Operate the slew lever.
4 The pressure gauge reading should be compared to
the technical data at the start of this section. If it is
outside the limits adjust the slew motor relief valve as
below.
E-292

Slew Motor Pressure Relief

TE-015
Note: If the water-proof slew lock solenoid valve is not
removed. Full slew pressure can not be read.
Note: Pressure measurement is also possible on the slew
motor, upper section.
5
6
C030150-1
2 ) pressure gauge
7
Note: If both relief valves are removed at the same time,
mark them left and right to facilitate re-assembly in the
correct position.
8
graphicA335121I
9813/5100-1
Section E - Hydraulics
Hydraulic System Test Procedures
Slew Motor Pressure Relief
If the readings are outside the limits, continue as
below.
Pressure Adjustment
a Make the machine safe, refer to Section E,
Service Procedures.
b Remove relief valve to be adjusted.
c The difference between the set pressure and the
present pressure determines the number of shims
E required for adjustment.
Remove the relief valve assembly from the slew
motor.
Disassembly
a Place the relief valve in a vice and remove the cap
A with a 14 mm hexagonal socket, take out the
piston C, liner B poppet E, spacer D, shims E and
spring F.
F
D
B
Fig 24.
b Add shim to increase pressure. Remove shim to
decrease pressure.
E
C
A
A405850-C1
E-292