LABEL 4169496 - Caterpillar

Inspection
Belt tension should be checked initially between the first 20 to 40 hours of engine operation.
Illustration 1 g06114636Inspect the condition of the serpentine belt. Over time the belt ribs will lose material (C). The space between the ribs will increase (D). The loss of material will cause the pulley sheave to contact the belt valley. This will lead to belt slippage and accelerated wear (E). Replace the belt if the belt is worn or frayed.For applications that require multiple drive belts, replace the belts in matched sets. Replacing only one belt of a matched set will cause the new belt to carry more load because the older belt is stretched. The additional load on the new belt could cause the new belt to break.If the belts are too loose, vibration causes unnecessary wear on the belts and pulleys. Loose belts may slip enough to cause overheating.If the belts are too tight, unnecessary stresses are placed on the pulley bearings and on the belts. This may shorten the service life of the components.Inspect the condition and adjustment of the alternator belts and accessory drive belts (if equipped).To check the belt tension, apply 110 N (25 lb ft) of force midway between the pulleys. A correctly adjusted belt will deflect 9 mm (0.35 inch) to 15 mm (0.59 inch).Alternator Belt
Illustration 2 g01154344
Typical alternator mounting
(1) Adjusting nuts
(2) Mounting bolt
(3) Mounting bolts
Slightly loosen mounting bolt (2) and mounting bolt (3). Slightly loosen adjusting nut (1).
Move the pulley to adjust the belt tension.
Tighten the following: adjusting nuts (1), mounting bolt, (2) and mounting bolt (3). Refer to the Specifications, SENR3130 for the proper torques.
Install the belt guard. Refer to the Specifications, SENR3130 for the proper torques.If new belts are installed, check the belt tension again after 30 minutes of engine operation at the rated rpm.Drive Belt for the Air Compressor (If Equipped)
Illustration 3 g01389673
(4) Drive belt for the air compressor
(5) Mounting boltsLoosen the four mounting bolts from the bracket that holds the air compressor.
Illustration 4 g01389675
Side view of the air compressor and pulley
(6) Bolt
(7) Adjusting boltLoosen bolt 6. Loosen bolt 7. Slide the air compressor closer to the pulley. Remove the old belt. Install a new belt.Slide the air compressor into position. Tighten bolt 7. Refer to Specification, SENR3130, "Torque Specifications" for the correct torque.Tension the belt.Tighten the four mounting bolts (5). Refer to Specification, SENR3130, "Torque Specifications" for the correct torque.