Check Fan Belt Tension, Adjust - Komatsu D61EX-12 Operation And Maintenance Manual

SERVICE PROCEDURE

CHECK FAN BELT TENSION, ADJUST

INSPECTION
The belt should normally deflect by 6 to 7mm (0.24 to 0.28in)
when pressed with the finger (with a force of approx. 59N
(6kgf)) at a point midway between the tension pulley and fan
pulley.
ADJUSTMENT
1. Loosen bolts and nuts(1), (2), (3), (4) and (5).
2. Turn nut(6) clockwise, then move tension pulley(7) to
adjust the belt tension so that the deflection is about 7mm
(0.28in) when pushed with a force of 59N (6kgf).
3. Tighten the bolts and nuts(1), (2), (3), (4) and (5) to fix
tension pulley(7) in position.
REMARK
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.
If any pulley is defective, ask your Komatsu distributor to replace it.
If any belt has stretched and there is no allowance for adjustment, or if there are cuts or cracks on any belt,
replace both belts at the same time.
When adjusting the V-belt, do not push the tension pulley directly with a steel bar, etc., but put a wood piece,
etc. between the pulley and bar.
After replacing the V-belt, operate for 1 hour, then check and adjust the belt tension again.
Special tools are required to replace the flat belt used to drive the alternator and water pump. Ask your
Komatsu distributor to replace that belt.
4-46
MAINTENANCE