How to Check Your Car’s Serpentine Belt for Wear

Although EPDM serpentine belts are superior to older models, it’s not as easy to tell when they’re worn out. Here’s how to check for serpentine belt wear using a specialized tool.

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Checking a serpentine belt for wear

Checking a serpentine belt for wear

Starting in 2000, some carmakers began installing a new kind of serpentine belt made of ethylene propylene diene monomer (EPDM). The new belts last much longer and handle the heat better than the older neoprene formulations. That means fewer belt changes over the life of your vehicle. In fact, EPDM can go almost 160,000 kilometres between changes! But since EPDM doesn’t crack like the old neoprene belts, you can’t do a visual check.

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Use a belt wear gauge

Use a belt wear gauge

The only way to gauge belt wear is with-you guessed it-a belt gauge. DIYers can get a free belt wear gauge at

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Measure your serpentine belt's grooves

Measure your serpentine belt’s grooves

The gauge measures groove depth to determine wear. Lay the wear gauge in the ribs on the serpentine belt and run your finger across them. If the gauge sits flush with the top of the ribs, the belt is worn out.

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Don't be fooled by low-price belts

Don’t be fooled by low-price belts

If it’s time to chuck your EPDM belt, replace it with the same kind. Don’t be fooled by low-price belts. They’re usually made from neoprene. Also, if your car has a neoprene belt and it’s cracked, consider replacing it with EPDM.

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