4 - 9
Auxiliary Relief Valves (continued)
Boom Ram
1
Prepare the machine
a
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
).
b
Connect a 0 - 400 bar (0 - 6000 lb/in
2
) pressure
gauge and adaptor to port
G2
on the hydraulic
pump (see view
A
on page 4 - 1).
2
If not already done, temporarily increase the pressure
setting of the MRV (see
Auxiliary Relief Valves
,
General
, step 2).
3
Start the engine, lower the gate lock lever and run the
engine at maximum no-load speed in the
S
mode.
4
Pressure Adjustment
Boom up
Note:
For accurate setting, the pressure should be adjusted
up
to the required level. Release lock nut
X
. Adjust setting
screw
Y
to indicate a pressure below the required level and
then bring the pressure back up for final setting. Tighten lock
nut
X
.
a
Fully raise the boom and then continue to operate
the right control lever as at
A
.
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 ARV
B
.
Section E
Hydraulics
9803/6020
Section E
4 - 9
Issue 1
Pressure Testing
12
SL
MODE
A
A
B
B
C
C
284430
292530
292490
289910
Front
X
X
Y
Y
Summary of Contents for JS70
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Page 189: ...Section E Section E Hydraulics 9803 6020 Issue 1 33 4 33 4 Control Valves Control Valve 291360...
