Accessory Belt - Water Pump/Alternator

Accessory belts keep everything turning off of the crank pulley.

It's easy to see when the belts are beginning to wear. Visually, the belt will begin to glaze on the underside, making it far less effective. Cracks can appear on the back of the belt from “dry rot” caused by exposure to engine heat or age. Squealing is common on worn belts which basically means that the belt is slipping on pulleys. In either case, your vehicle needs a new belt.