Komatsu PC20R-8 Shop Manual page 157

TESTING AND ADJUSTMENTS
PC27R-8
1. Control of operating pressure (unloading valve)
1 - Remove the plug (1) of pump P1 and mount a
pressure adapter.
2 - Connect a pressure gauge E1 (60 bar).
3 - Start the engine and bring it up to high idling with
all levers in neutral position.
4 - Check the pressure.
H Normal pressure:
The unloading valve cannot be re-adjusted. If
the pressure differs from the normal value the
valve must be substituted.
2. Control the operating pressures of the working
equipment and machine travel
1 - Remove the plug (1) of pump P1 and mount a
pressure adapter.
2 - Connect a pressure gauge E2 (400 bar) or E3
(600 bar).
3 - Start the engine and bring it up to high idling.
4 - Check the pressure for each movement with the
command lever at the end of its stroke and with
the pressure stabilised.
To check the pressure of the working equip-
ment, push the piston to the end of its stroke.
To check the pressure of machine travel, in-
sert a block "A" between the chassis and
the sprocket wheel.
H Normal pressures:
Working equipment and travel:
3. Check the operating pressure of the turret
swing
1 - Set the main relief valve of the control valve to a
value higher by 20 bar than the maximum pres-
sure to be checked.
2 - Remove the caps (1) of the swing motor and
mount the pressure adapters.
3 - Connect a pressure gauge E2 (400 bar) or E3 (600
bar).
Insert the turret swing locking-pin.
4 - Start the engine and bring it up to high idling.
5 - Check the pressure for a swing to the right and a
swing to the left, bringing the lever of the left-hand
PPC valve to the end of its stroke and with the
pressure stabilized.
H Normal pressure:
6 - Restore the setting of the main relief valve.
PC20R-8 PC27R-8
2
35w5 kg/cm (34.3w4.9 bar)
2
210 10 kg/cm (206 10 bar)
2
215 5 kg/cm (211 5 bar)
CONTROL AND REGULATION OF THE PRESSURES
IN THE HYDRAULIC CIRCUITS
E
1
1
1
1
3
E
A
3
E
RKPA2250
RKPA2260
RKPA3870
RKPA2270
20-41