4 - 6
Pilot Relief Valve
1
Prepare the Machine
Put the operator levers into neutral and lower the gate
lock lever. Start the engine and park the machine on
level ground. Operate the dipper out and lower the
boom to set the bucket on the ground. Lower the blade
onto the ground. Stop the engine. Release the hydraulic
oil tank pressure. (See
Releasing Tank Pressure
).
2
Before testing the Pilot Relief valve (K), connect a 0-100
bar (0-1500 lb/in
2
) pressure gauge to test point G3 (see
view A on page 4-1).
Note:
The following machines will need to have a G3 test
point retrospectively fitted:
Machine Numbers
695501-695528, 695530-695531, 695534-695535
3
Start the engine and confirm that the engine is at its
maximum no-load speed and it is in the
S
mode. 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 pilot relief valve as below.
4
Stop the engine
.
5
The valve is adjusted by placing shims at position
A
.
Shim Adjusting method
Remove the plug
1
and pull out the spring
2
, the spool
3
and the shim
5
.
Remove the poppet
4
, Care must be taken not to
displace the pressure adjustment shim in the poppet
brim section. Install the spring
2
, the spool
3
and the
shim
5
and tighten the plug
1
. Add the correct number
of shims to the poppet brim section.
Note:
One shim is equivalent to 1 bar in pressure. (Shim part
number LMC 0110).
6
After locking, check the relief pressure again.
If it is not within the limits above, perform steps 3 to 6
again.
7
Stop the engine, release the tank pressure (see
Releasing Tank Pressure
) and then remove the
pressure gauge.
Section E
Hydraulics
9803/6020
Section E
4 - 6
Issue 1
Pressure Testing
A
A
284430
292440
292470
Summary of Contents for JS70
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