Komatsu F30791, Shop Manual

Page: 167 / 298

ELIMINATION OF RESIDUAL PRESSURES - PRESSURISATION
OF THE TANK
20-51
TESTING AND ADJUSTMENTS
ELIMINATION OF RESIDUAL PRESSURES -
PRESSURISATION OF THE TANK
1. Elimination of pressures from the hydraulic cir-
cuits.
1 - Rest the working equipment on the ground and
stop the engine.
2 - Turn the ignition key to the position « I » and move
the command lever in all directions to release all
pressure in the main hydraulic circuits and the
servo-controls .
3 - Return the ignition key to the position « O » (OFF)
and remove it.
4 - Put the safety device lever into its «LOCKED» po-
sition.
2. Elimination of pressure in the tank
The hydraulic oil tank is of the sealed and pres-
surised type.
When tubes are to be removed or disconnected
for controls or repairs, or when caps are re-
moved, tank pressure must be eliminated using
the following method:
1 - Rest the working equipment on the ground and
stop the engine.
2 - Slowly loosen the oil-refuelling cap in order to re-
lease residual pressure.
3. Pressurising the tank
H This operation should be performed every time
the oil-refuelling cap is moved for removal of the
tubes or other hydraulic equipment.
1 - Start the engine and position the machine as in
the figure.
2 - Stop the engine, loosen the tank cap (1) and then
close it again.
H This operation lets air into the tank when the
level of the remaining oil is at minimum.
3 - Start the engine and lower the working equipment
to the ground.
PC20R-8 PC27R-8
RKPA2440
1
RKP04720