4 - 8
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. 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
9803/6410
Section E
4 - 8
Issue 1
Pressure Testing
AA
A296530
289910
XX
YY
BB
296590a
306490