Check And Adjust Fan Belt Tension - Hitachi ZAXIS 135US-6 class Operator's Manual

Hydraulic excavator

Table of Contents

Check and Adjust Fan Belt Tension

--- every 250 hours (first time after 50 hours)

IMPORTANT: Loose fan belt may result in insufficient

battery charging, engine overheating, as well as a

rapid, abnormal belt wear. Belts that are too tight can

damage both bearings as well as the belts.

Check fan belt tension by depressing the midpoint between

the fan pulley and the alternator pulley by your thumb

with a depressing force of approximately 98 N (10 kgf ).

Deflection must be within the value illustrated in the right.

Visually check the belt for wear. Replace if necessary.

Adjust Drive Belt Tension

1. Loosen lock nut (1) and alternator lower mounting bolt

2. Rotate tension adjust bolt (2) to adjust the belt tension.

3. After completing adjustment, tighten lock nut (1) and

alternator lower mounting bolt (3) to specifications.

Standard Tightening Torque:

Nut : 25 N·m (2.5 kgf·m)

Bolt : 52 N·m (5.2 kgf·m)

IMPORTANT: When a new belt is installed, be sure to re-

adjust the tension after operating the engine for 3 to 5

minutes at slow idle speed to be sure that the new belt

is seated correctly.

98 N (10 kgf)

Crank Pulley