Komatsu HD785-5, Operation & Maintenance Manual

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MAINTENANCE
SERVICE PROCEDURE
CHECK ALTERNATOR BELT, ADJUST
CHECKING
The belt should normally deflect by above 15 mm (0.6 in) when
pressed with the thumb (with a force of approx. 58.8 N (6 kgf) at a
point midway between the drive pulley and alternator pulley.
ADJUSTING
1. Loosen bolt (1) and lock nut (2).
2. Rotate adjusting nut (3) so that the deflection is approx. 15 mm
(0.6 in) (at a force of approx. 58.8 N (6 kgf).)
3. After adjustment, tighten lock nut (2) and bolt (1) securely.
REMARK
Check each pulley for breakage and wear of the V-groove. In
particular, check that the V-belt does not touch the bottom of the
V-groove.
If any abnormality is found, ask your Komatsu distributor for
replacement of the pulley.
If the V-belt is so lengthened that it cannot be adjusted any more
or if it has any cuts or cracks, replace it.
When adjusting the V-belt, do not press the alternator directly
with a bar, but put a wood piece, etc. in-between them.
If the V-belt has been replaced with a new part, there will be
initial elongation, so inspect and adjust it again after one-hour of
operation.
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