Knowing Car Maintenance: Checking Accessory Belts

Belt CheckThe last in the series on simple car maintenance, this week’s post is about checking your car’s accessory belt or belts. Most newer vehicles use a serpentine multi-accessory drive belt. It is a single ribbed belt that drives all the accessories, air conditioning system, power steering, alternator as well as other pumps and accessories. Some older cars and trucks may have separate accessory belts.

Belts wear and become damaged over time. A broken accessory belt could mean serious damage to the engine or its systems. Periodically checking the accessory belt or belts will help you catch and replace a bad belt long before it snaps.

Here is what to do:

Inspect belt for signs of wear. With the engine off and cool, inspect the belt or belts. In addition to doing a visual check, feel the condition of the belts checking for cracks, fraying, splits or brittle areas.

Look for places on the belt where the rubber is slick looking. Slick spots can cause a belt to slip and may be precursors to overheating and cracking. 

Check the pulleys. Look for rubber deposit build-up spots or worn spots that could catch the belt and cause it to snap.

Note the belt tension. Check the tension on the longest length of the belt; it should be tight, with little or no give.

If you hear squealing sounds from the engine while you are driving, this could mean a worn, loose or damaged belt. If you are not sure about the sounds you are hearing, listen to how the engine sounds with the hood up. Make sure the car in park, with the parking brake on, and have someone accelerate the engine while you listen. When you do this, be sure to keep a safe distance from belts and components while the engine is running.

If you confirm there is a squealing noise, or if you are unsure about accessory belt condition, be sure to get your car in for service, before you have any serious problems.