SENSOR AS 5139957 - Caterpillar

Belts
Stop the engine to inspect the belt.
Open the engine access door. Refer to Operation and Maintenance Manual, "Access Doors and Covers".
Illustration 1 g01209498
Remove the four bolts (1) on the top of the guard. Loosen the two bolts (2) on the bottom of the guard.
Slide the guard upward from bottom bolts. Remove the guard for the V-belt.
Illustration 2 g01209499
Inspect the condition of the belt (3) and the adjustment of the belt. The belt should deflect 10 mm (0.39 inch) under a straight pull of 44 N (10 lb). This measurement should be taken between the alternator pulley and the crankshaft pulley. Note: A 144-0235 Borroughs Belt Tension Gauge may be used to measure belt tension. This measurement should be taken between the alternator pulley and the crankshaft pulley. Refer to the following table for belt tension.
Table 1
Belt Tension
Initial Belt Tension
Used
400 to 489 N (90 to 110 lb) 267 to 356 N (60 to 80 lb)
Loosen the mounting bolt (4). Loosen the adjusting locknut (5).
Move the alternator until the correct tension is reached.
Tighten the adjusting locknut. Tighten the mounting bolt.
Recheck the belt deflection. If the amount of deflection is incorrect, repeat step 5 to step 8. Air Conditioner (if equipped)
Note: If your machine is equipped with an air conditioner, use the same procedure and the same measurements for the belt tension.
Inspect the condition of the belt and the adjustment of the belt. The belt should deflect 10 mm (0.39 inch) under a straight pull of 44 N (10 lb). This measurement should be taken between the air conditioner compressor pulley and the crankshaft pulley.
Illustration 3 g01279933
Loosen the mounting bolt (6) for the air conditioner compressor. Loosen the adjusting locknut (7) for the air conditioner compressor.
Move the air conditioner compressor until the correct tension is reached. Note: A hole (8) in the bracket has been provided to aid with the adjustment of the tension.
Tighten the adjusting locknut. Tighten the mounting bolt.
Recheck the belt deflection. If the amount of deflection is incorrect, repeat step 2 to step 4. Finish
Apply thread lock compound to the threads on bolts (1).
Illustration 4 g01364054
Install the guard for the V-belt (9). Ensure that the guard is inserted between the mounting bracket (10) and the spreader plate (11) before you tighten the bolts (2). Tighten the bolts (2) to 15 3 N m (11 2 lb ft).
Illustration 5 g01209498
Tighten the bolts (1) to 12 3 N m (9 2 lb ft). Note: Start all the bolts (1) in the holes before you start tightening the bolts. This practice helps align all the holes.
Close the engine access door.