State Street Auto Repair

State Street Auto Repair Blog

What Happens if a Serpentine Belt Breaks?


The serpentine belt is also known as an alternator belt, fan belt, or accessory drive belt. It is powered by a car’s engine to spin or “drive” several mechanical components in the engine, and is responsible for providing power to vital systems, such as the electrical system, the power steering system, the cooling system and the A/C system. Some vehicles’ water pumps, radiator fans, and power brakes are also dependent on the serpentine belt.

If your serpentine belt wears out, becomes damaged or contaminated, or breaks, engine accessories will not be able to spin at the proper speed, leading to decreased power to the electrical system. This can lead to a sudden lost of power assist for the steering system, leading to the steering wheel all-of-a-sudden becoming very hard to turn. A broken serpentine belt may stop the water pump from circulating coolant through the cooling system, causing the engine can overheat. And it may stop the alternator from generating power to operate the vehicle’s electric/electronic systems and recharge the battery - the headlights will dim, the radio will not work, and the battery will die.

Your car’s owner's manual will advise you when to replace your serpentine belt, but most vehicle manufacturers recommend inspection and replacement of the serpentine belt between 60k and 90k miles. Advances in material technology allow some belts to last more than 100k miles. State Street Auto Repair technicians can inspect the belt for cracks and measure thickness to determine if it's close to failure. Inspecting and replacing your serpentine belt on a regular schedule will save you from a dangerous breakdown.

Becca Ralphs