Komatsu PC400LC-5 Operation & Maintenance Manual page 200

24. SERVICE PROCEDURE
24.5.6 CHECK FAN BELT TENSION, ADJUST
Checking
The belt should normally deflect by about 6 to 7 mm (0.23 to 0.28
in) when pressed with the finger (with a force of approx. 6 kg (13 lb)
at a point midway between the alternator pulley and fan pulley.
Adjusting
1.
Loosen bolts and nuts @ and 0.
2. Loosen the lock nut and shift alternator @ slightly, so that the
belt deflects about 6 to 7 mm (0.23 to 0.28 in) (with a force of
approx. 6 kg (13 lb)).
When adjusting the V-belt, do not attempt to push alternator @
directly with a bar or the like, but use a wood pad to prevent damage
to the core.
Fan pully
6-7mm
(0.23 - 0.26 in)
'\
._
FEY
Alternator
Crankshaft pully
AD098800
3. Tighten the bolts and nuts @ and @ to fix alternator @ in
position.
4. Check each pulley for damage, wear of the V-groove, and wear
of the V-belt. In particular, be sure to check that the V-belt is not
touching the bottom of the V-groove.
5.
Replace belt if it has stretched, leaving no allowance for adjust-
ment, or if there is a cut or crack on belt.
6. When the new belt is set, readjust it after operation for an hour.
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