Control And Adjustment Of - Komatsu PC20R-8 Shop Manual

TESTING AND ADJUSTMENTS
CONTROL AND ADJUSTMENT OF THE TRACK-SHOE TENSION
1. Test
H Test conditions:
Solid, flat ground.
.
Working equipment: resting on the ground.
.
1 - Only for machines with rubber track-shoes
Move the machine backwards and forwards until
the track-shoe joint (mark M) is uppermost and
halfway between the sprocket wheel and the
track-shoe stretcher wheel.
2 - Rotate the revolving frame 90ë towards the side of
the track-shoe to be checked.
3 - Close the bucket, bring the arm perpendicular to
the ground and rest the bucket on the ground.
4 - Force the boom downwards until the track-shoe to
be checked is completely raised.
5 - Measure the distance «A» in the following posi-
tions:
PC20R-8: Between the 2
and the track shoe.
PC27R-8: Between the 3
and the track shoe.
H Standard measurements
Model RUBBER TRACK-SHOE STEEL TRACK-SHOE
PC20R-8 A=10 ± 15 mm
PC27R-8 A=10 ± 15 mm
2. Adjustment
If the track-shoe tensions do not fall within permissible
limits, adjust them as follows:
H On completion of the adjustment and before en-
gaging the greasing pump G1, thoroughly clean
the grease nipple and surrounding area.
1 - If the tension is too low.
Inject grease through the grease nipple (1) using
the grease pump G1.
H If difficulties are found when injecting the
grease, move the machine slowly backwards
and forwards over a short distance.
2 - If the tension is too high.
Slowly loosen the union (2) in order to let grease
out of the valve.
The grease in the stretcher cylinder is under
pressure and could seriously injure the op-
erator. For this reason the valve should not
be loosened for more than one turn.
H If the grease does not come out easily,
move the machine slowly backwards
and forwards over a short distance.
20-38
CONTROL AND ADJUSTMENT OF THE TRACK-SHOE TENSION
nd
sprocket track roller
rd
sprocket track roller
A=10 ± 30 mm
A=10 ± 30 mm
100 ± 150 mm
100 ÷ 150 mm
" "
A
2
1
PC20R-8 PC27R-8
RKP04690
RKPA3250
RKPA3260
RKPA3270