The Chevy Astro van has a serpentine drive system that transfers torque from the crank pulley to the various engine accessories by way of a serpentine belt. The belt can slip on a pulley if the accessory is malfunctioning, or if the accessory’s pulley bearings are failing. However, it doesn’t take a malfunction to cause a belt squeal. The most common source of belt noise occurs when moisture finds its way onto the belt system and gets between the belt and the pulleys; the belt will slip and squeal. Moisture can adhere to the belt from morning dew, a coolant leak or heavy rainfall.
Put safety glasses on, start the Astro van, and raise the hood.
Position yourself so you can see as much of the serpentine belt as possible, and spray a short blast of WD-40 on the ribbed side of the belt. Wait several seconds. If the squeak does not go away, spray another blast. Continue until the squeak stops. WD-40 is a water-displacement lubricant, which will expel the water from the belt and pulley surfaces. If you are standing on the side of the engine well, stand in the opposite direction of the belt travel. This will minimize the amount of deflected spray that hits you.
Spray a quick blast of rubber protectant, such as Meguiar’s Vinyl & Rubber Protectant, Armor All or Pinnacle Vinyl & Rubber Protectant, onto the ribbed side of the belt. This will treat the rubber in the belt, providing longer life and minimizing any damage done by the water intrusion. You might experience brief slipping in the belt when rubber protectant is first applied, but it will go away after a moment or two.
