Komatsu F30791, Shop Manual

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CONTROL AND ADJUSTMENT OF THE TENSION OF THE FAN BELT
20-28
TESTING AND ADJUSTMENTS
CONTROL AND ADJUSTMENT OF THE
TENSION OF THE FAN BELT
1. Checking the tension
1 - Depress the belt (1) at the centre of the section be-
tween the alternator (2) and the pulley (3) that
drives the water pump. Check the flexion.
At a pressure of 10 kg (98 N) the flexion should be
10 ± 15 mm. If this value is not found, adjust the
belt tension.
H With a new belt the flexion should be 7 ± 9 mm.
2. Adjusting the belt tension
1 - Loosen the screws (4) that secure the alternator
(2) and the screw (5) that secures the belt-tighten-
ing stop.
2 - Rotate the alternator (2) to give the belt (1) the cor-
rect tension and tighten the screws (4) and (5).
3 - Check the belt (1) tension.
H If the belt has been replaced with a new one,
check the tension again after about 20 hours of
operation.
Screws fastening the alternator to the timing
system cover: 45 ± 54 Nm
Screws locking the support: 25 ± 32 Nm
PC20R-8 PC27R-8
RKPA2170
3
5
1
4
2
RKP04800
10
⫼
15 mm
Puleggia
albero motore
3
2
1
Crankshaft
pulley
10 ± 15 mm