Arm Assembly; Removal; Installation - Komatsu PC20R-8 Shop Manual

REMOVAL AND INSTALLATION
REMOVAL OF THE ARM ASSEMBLY
Lower the working equipment to the ground with all
safety devices engaged with the arm in a vertical po-
sition and the bucket curled.
1 - Stop the engine and release the pressures from buck-
et cylinder and from optional working equipment cir-
cuit.
2 - Attach a block «a» beneath the cylinder (1) and re-
move the pin (2).
3 - Start the engine and retract the piston (3).
4 - Stop the engine and release the residual hydraulic
pressures. (For details, see «20. CONTROLS AND
ADJUSTMENTS»).
5 - Disconnect the tubes (4) of bucket cylinder command.
H Plug the tube and the holes on the cylinder to pre-
vent entry of impurities.
6 - Disconnect the delivery and exhaust equipment
tubes (5).
H Plug the tubes to prevent entry of impurities.
7 - Remove the pin (6) and take out the arm complete (7).
Arm complete: PC20R-8: 115 kg
INSTALLATION OF THE

ARM ASSEMBLY

To install, reverse the removal procedure.
.
Internal bushings: ASL800040
H Insert the shims on both sides of the piston rod.
When aligning the positions between the hole and
the pin, turn the engine over at low idling.
Do not insert fingers in the holes to check alignment.
H Insert the shims on both sides of the arm.
When aligning the positions between the hole and
the pin, do not insert fingers in the holes to check
alignment.
Start the engine to circulate the oil and bleed the air
.
from the cylinder.
H After bleeding the air, stop the engine and check
the oil level in the tank.
PC20R-8 PC27R-8
PC27R-8: 160 kg
1
3
2
5
4
7
ARM ASSEMBLY
RKPA3750
A
RKPA3572
6
RKPA3760
30-75