SFWR GP-A1000 5265170 - Caterpillar

Inspect Belts
You should inspect the belts in your engine in order to get the maximum performance out of your engine. The belts should be inspected for wear and for cracks. Check the belt tension. If the belts are loose, the belts will slip. Belts that slip will cause poor performance of the alternator.
Inspect the belts.
Inspect the tension of the alternator belt.To check the belt tension, apply 110 N (25 lb) of force to the belt. The force must be applied midway between the pulleys. If the belts are properly adjusted, the belts will deflect 10 to 15 mm (.4 to .6 inch).Check the adjustment on new belts after the new belts have operated for 30 minutes. For multiple belt drive applications, replace the belts in matched sets.If only one belt of a matched set is replaced, the new belt will carry more load than the old belts. The old belts will be stretched. The additional load on the new belt could cause the new belt to break.