Komatsu PC88MR-10 Shop Manual page 396

30 Testing and adjusting
Hydraulic system
1) Start the engine, and set the working mode
to power mode (P).
2) Run the engine at high idle, operate the
blade control lever to lower, and measure the
oil pressure when relieving.
4. Testing blade (RAISE) relief pressure
1) Start the engine, and set the working mode
to power mode (P).
2) Run the engine at high idle, operate the
blade control lever to raise, and measure the
oil pressure when relieving.
5. After finishing the test, remove the testing tools,
and restore the machine.
Adjusting
(PC88MR-C000-270-K-01-A)
1. Adjustment of swing relief pressure
a If the swing relief pressure is not normal,
adjust safety valve (2) of the swing motor
according to the following procedure.
Do not turn end cap (3) in a
counterclockwise more than once. More
turns may cause the cap to be jumped
out.
1) Loosen lock nut (4) of safety valve (2) and
turn end cap (3) to adjust the pressure.
a Rotate the adjustment screw:
turned clockwise, the set pressure
increases.
turned counterclockwise, the set
pressure decreases.
a Quantity of pressure adjustment per turn
of adjustment screw:
4.8 MPa {49.3 kg/cm
2) After finishing the adjustment, tighten lock
nut (4).
Lock nut:
93.2 to 117.7Nm {9.5 to 12kgm}
30-46
2 }
3) After finishing the adjustment, check the oil
pressure again according to the above
procedure.
2. Adjusting blade (LOWER) relief pressure
a If the blade (LOWER) relief pressure is
abnormal, adjust main relief valve (5)
according to the following procedure.
Do not turn end cap (6) in a
counterclockwise more than once . More
turns may cause the cap to be jumped
out.
1) Loosen lock nut (7) of main relief valve (5)
and turn end cap (6) to adjust the pressure.
a Rotate the adjustment screw:
turned clockwise, the pressure is
increased.
turned counterclockwise, the pressure
is decreased.
a Quantity of adjustment per turn of
adjusting screw:
19.6 MPa {200 kg/cm
2) After finishing the adjustment, tighten lock
nut (7).
Lock nut:
39 to 49 Nm {4 to 5 kgm}
}
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PC88MR-10