A fan belt is the belt located in the engine bay that runs the engine's cooling fan as well as other components. The belt is usually driven off of the crankshaft and in turn controls the fan as well as the water pump, power steering pump and alternator, though this varies from car to car. Fan belts should be inspected regularly and replaced if needed. If a fan belt fails, the car's engine can overheat.
Open the hood to access the engine. Locate the radiator and the fan. The belt will run the fan and any other components that it controls on a pulley.
Loosen the tension on the fan belt. This will vary depending on the make and model of your car. Some belts will be loosened by a bolt that holds the alternator bracket to the engine. As the bolt is loosened with a wrench, the bracket will allow the alternator to move and release tension on the belt. Other models have a fan belt tensioner that automatically tensions the belt. To loosen this type, use a wrench to loosen the nut in the tensioner. Consult your owner's manual for specifics.
Remove the belt by sliding it off of the various pulleys that it is routed over. Note the orientation of the belt as you remove it so the new belt is installed correctly. Some cars will have a small diagram mounted near the belt that shows how the belt is routed. You can also draw a diagram before removing the old belt.
Slide the new belt over the pulleys in the same orientation as the old belt. Belts can be purchased at the dealer that sells your make of car as well as at any auto parts store. Tighten the belt with the bracket bolt that holds it tight or with the belt tensioner pulley. Some models have self-adjusting tensioners, so the belt is simply installed and the tensioner is slid into position and applies the appropriate amount of tension to the belt. The belt should be tight enough that it is not easy to press, but it should deflect a little when you press on it hard with your finger.
