322B, 322B L, 325B and 325B L Excavators Caterpillar

Your engine can be equipped with a water pump belt, with a fan drive belt and with accessory drive belts. Your engine can also be equipped with an alternator belt. For maximum engine performance and maximum utilization of your engine, inspect the belts for wear and for cracking. Check the belt tension. Adjust the belt tension in order to minimize belt slippage. Belt slippage will decrease the belt life. Belt slippage will also cause poor performance of the alternator and of any driven equipment.

If new belts are installed, recheck the belt adjustment after 30 minutes of operation. If two belts or more are required for an application, replace the belts in belt sets. If only one belt of a matched set is replaced, the new belt will carry more load. This is due to the fact that the older belts are stretched. The additional load on the new belt could cause the new belt to break.

Water Pump Belt

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Illustration 1	g00323083

1. To check the belt tension, apply 110 N (25 lb) of force midway between the pulleys. Correctly adjusted belts will deflect 13 to 19 mm (1/2 to 3/4 inch).

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Illustration 2	g00105241
Typical example (1) Mounting bolt (2) Bracket bolt (3) Idler pulley (4) Square hole

2. To adjust the water pump drive belt, loosen mounting bolt (1) and bracket bolt (2) .

3. Move idler pulley (3) in order to achieve the correct adjustment.

4. If necessary, use a pry bar in square hole (4) in the mounting bracket.

5. Tighten mounting bolt (1) and bracket bolt (2) .

6. If a new belt is installed, run the engine at rated speed for thirty minutes. Check the bolt torque. Readjust the belt, if necessary.

Alternator Belt and Fan Drive Belt

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Illustration 3	g00323083

1. To check the belt tension, apply 110 N (25 lb) of force midway between the pulleys. Correctly adjusted belts will deflect 13 to 19 mm (1/2 to 3/4 inch).

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Illustration 4	g00102652
(1) Bracket bolt (2) Mounting bolt (3) Hole

2. To adjust the alternator belt and the fan drive belt, loosen bracket bolt (1) and mounting bolt (2) on the alternator bracket.

3. To achieve the correct adjustment, move the alternator inward or move the alternator outward, as required.

4. If necessary, use a pry bar in hole (3) in the alternator bracket.

5. Tighten mounting bolt (2) and bracket bolt (1) .

   Note: The alternator shaft nut must be tightened to a torque of 50 ± 5 N·m (37 ± 4 lb ft).

6. If new belts are installed, check the belt adjustment again after 30 minutes of engine operation at the rated speed.

Air Conditioner Belt

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NOTICE
The V-belt must be tensioned correctly. Failure to tension the belt properly could cause damage to the belt and/or to the air conditioner compressor.

Illustration 5	g00323083

1. Apply approximately 98 N (22 lb) force midway between the pulleys.

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Illustration 6	g00529420
(1) Nut (2) Adjusting bolt

2. Measure the deflection of the belt. The belt should deflect 18 to 24 mm (3/4 to 15/16 inch).

3. If the deflection is not correct, loosen nut (1). Turn adjusting bolt (2) in order to adjust the belt tension.

4. When the adjustment is correct, tighten nut (1) to a torque of 38 ± 7 N·m (28 ± 5 lb ft).

5. Check the deflection again.

   Note: If a new belt is installed, check the belt adjustment again after 30 minutes of engine operation at the rated speed.