jcb JS300 Service Manual page 948

Boom Ram
Boom Up
1 Prepare the machine
a Operate the dipper out and lower the boom to set
the bucket on the ground.
Fig 8.
b Make the machine safe, refer to Section E,
Service Procedures.
c Connect a 0 - 400 bar (0 - 6000 lb/in
gauge and adaptor to port TP1 on the hydraulic
pump.
2 Increase MRV Pressure, refer to Section E, Service
Procedures.
3 Start the engine, lower the gate lock lever and run the
engine at minimum no-load speed in the E mode.
a Fully raise the boom and then continue to operate
the right control lever as at A.
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Hydraulic System Test Procedures
C030150-1
2 ) pressure
b The pressure gauge reading should be compared
to the technical data at the start of the section. If it
is outside the limits, adjust the ARV.
Note: For accurate pressure setting, the pressure should
be adjusted up to the required level. Release lock nut X.
Adjust setting screw Y to a pressure below the required
level and then bring the pressure back up for final setting.
Tighten lock nut X.
4 Restore Original MRV Pressure, refer to Section E,
Service Procedures.
9813/5100-1
Section E - Hydraulics
Auxiliary Relief Valves
A
Fig 9.
Fig 10.
C002690-C1
312460-C1
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