Komatsu PC20R-8 Shop Manual page 173

TESTING AND ADJUSTMENTS
4. Boom swing test
1 - Position the machine with the boom, arm and
bucket raised and with the revolving frame
turned 135ë to the left.
2 - Stop the engine and release the residual hydrau-
lic pressures.
3 - Disconnect from control valve the pipe (1) and
plug it.
H Plug the control valve union to prevent entry
of impurities
4 - Disconnect the boom swing cylinder hose (2) and
plug it.
5 - Attach a provisional tube on the head side to
catch any oil leakages.
6 - Start the engine and move the machine to a 15ë
slope.
7 - Stop the engine and check the position of the
boom for 15 minutes.
If the boom makes a rotating movement
.
the drift is due to the cylinder gaskets.
If the boom 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
1
2
RKP05040
RKPA2500
RKPA2510
RKP05050
20-57