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How to check serpentine belt wear

What do the alternator, water pump, air conditioner and power steering have in common? In modern cars, they are driven by serpentine belts. What you don’t want is for those long rubber bands to suddenly break while on the road, as you will lose all driven attachments and possibly the engine itself.
Existing serpentine belts have the ability to last 50,000 miles or more, and are durable. However, a quick checkup from time to time can help you avoid a lot of headaches. Here’s how to check your vehicle’s serpentine belt wear.

Listen and Learn Serpentine belts tend to make less noise due to wear and tear with age and use. In fact, a creaking belt is usually one of the first signs that a serpentine belt is about to be replaced. If your serpentine belt creaks or squeaks, whether it occurs at engine start or constantly, it’s time for a more thorough inspection.

While it’s tempting to cover up your belt squeaks with a product like a belt loop, it can actually make things worse. Not only are you ignoring one of the many signs of the short life of your serpentine belt, but some products can actually worsen the condition of your belt, increasing the chances of it breaking down more quickly.

Look for signs of wear Most serpentine belts tend to wear out gradually, which gives you plenty of warning.

Look for the glass at the top of the belt as well as the grooves. Friction between the belt and the drive pulley can leave glass stains. Poor belt alignment or poor automatic serpentine belt tension can cause slippage, resulting in glass.

Check for wear and cracks at the top and edges of the belt, as well as at the belt ribs. It is not uncommon for serpentine belts to lose their material as they age, especially if there is a belt alignment problem or a problem with one of the engine pulleys.

Check the tension of the serpentine belt by finding the furthest distance between the drive pulleys and pressing the center of the belt. A new, properly oriented viper belt should be tight and have a swivel distance of less than half an inch, while a worn belt may provide an inch or more.

Using a Wear Gauge If you are dealing with a serpentine belt made of ethylene propylene diene monomer or EPDM, you may not notice the traditional signs of wear mentioned above. Alternatively, EPDM belts tend to wear out in the same way as car tires. This means you will find gradual wear and tear that is difficult to see with the naked eye.

Belt wear gauges are useful for detecting signs of wear on EPDM serpentine belts. With the engine off, place the belt wear gauge on the serpentine belt with the gauge ribs screwed into the groove on the belt. Once the tool is in place, hold it in place with light pressure and try moving the gauge back and forth.

If the gauge stays in place with little or no movement, the belt has a lot of life. You may notice the chisel is slightly above the surface of the serpentine belt. If the gauge is laterally rocky and/or rests completely on the serpentine belt, this means that the belt material is worn enough to merit replacement.