Boom; Removal - Komatsu PC20R-8 Shop Manual

REMOVAL AND INSTALLATION
REMOVAL OF THE BOOM
Disconnect the negative terminal cable (±) from the
battery.
1 - Remove the arm assembly. (For details, see «RE-
MOVAL OF THE ARM ASSEMBLY»).
2 - Remove the arm cylinder. (For details, see «RE-
MOVAL OF THE ARM CYLINDER»).
3 - Remove the working beam (1).
4 - Stop the engine, and rest the boom (2) on a block «A».
5 - Stop the engine and move the PPC valve several
times to release pressures in the cylinder.
6 - Place a stand «B» beneath the cylinder (3).
7 - Remove the pin (4) and rest the cylinder on a stand.
8 - Start the engine and completely retract the piston rod
(5).
9 - Stop the engine and release the residual hydraulic
pressures. (For details, see «20. CONTROLS AND
ADJUSTMENTS»).
10 - Put a sling round the boom (2) and apply a slight ten-
sion to the cables.
11 - Disconnect the hoses (6) (N
prevent entry of impurities.
H Remove the wiring harness lock clips.
12 - Remove the pin (7) and remove the boom (2).
Boom: PC20R-8: 80 kg
PC27R-8: 126 kg
30-76
. 10); plug the tubes to
o
1
2
3
2
4
5
6

BOOM

RKPA3511
B
A
RKPA3770
RKPA3522
6
7
RKPA3780
PC20R-8 PC27R-8