Komatsu PC20R-8 Shop Manual page 171

TESTING AND ADJUSTMENTS
2. Arm test
1 - Position the machine with the arm completely ex-
tended and with the bucket teeth on the ground.
2 - Stop the engine and release the residual hydrau-
lic pressures.
3 - Disconnect the hoses (1) and (2) from the arm cy-
linder and plug them to prevent the entry of impu-
rities.
4 - Plug the hole of the arm cylinder on the head
side and attach a provisional tube on the base
side to catch any oil leakages.
5 - Start the engine and raise the boom.
6 - Stop the engine and check the position of the
arm for 15 minutes.
If the arm moves downwards the drift is due to
.
the cylinder gaskets.
If the arm does not move, the drift is due to the
.
control valve.
PC20R-8 PC27R-8
CONTROL OF HYDRAULIC DRIFTS -
ANALYSIS OF THE CAUSES OF A DRIFT
2
RKP05000
1
RKPA2480
RKP05010
20-55