Test 005: Checking The Operation Of The Main Hydraulic Spool - jcb JS300 Service Manual

Test 005: Checking the Operation of the Main Hydraulic Spool

F
E
Fig 6. Sectional view of valve block showing spool and pilot ports
A Cylinder port B
B Cylinder port A
C Pilot port a
D Valve block
E Main spool
F Pilot port b
Identify which is main directional spool for service being
tested, and which side of that spool is supplied pilot
pressure when service is operated in desired direction
Fit pressure gauges 0 - 60 bar (0 - 1000lb in
and also to port on opposite end of spool
Warm up hydraulic system to 50 °C (122°F)
Remove the hose from the spool port that is not being
selected and plug the hose.
Remove the hose from the spool end that is being selected
and plug the hose. Couple a hand pump (see Service
tools) with a pressure 60 bar (0 - 1000lbin
attached. (Instead of using a hand pump, the pressure
from the accumulator may be used by leaving the hose and
Pressure gauge attached, but will not be as accurate, and
should only be used if only full spool selection is being
measured.)
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Test 005: Checking the Operation of the Main Hydraulic Spool
A
2 ) to this port
2 )gauge
9813/5100-1
Section E - Hydraulics
Hydraulic System Fault Finding
B
D
lInsert a piece of stiff clean wire (Approximately 2 mm (0.08
in) diameter)) through the adapter in the port not being
selected until the spool end is felt.
Slowly select the spool from the selected end using the
portapower pack, measure the distance the spool moves
and check against the graph.
the accumulator pressure, turn on the machines ignition,
lower the controls Enable lever and select the service.
Note: The accumulator may require recharging by running
the engine for a short period).
Remove Spool cap from the main valve block and
withdraw the spool checking
imperfections, or any signs of sticking. Slide the spool in
and out of the valve block, rotating it at the same time
checking for smoothness.
C
K Fig 7. ( T
E-257). (If using
for any scratches/
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