Inspection

• When inspecting a serpentine belt, cracks are the most important thing to look for. Check the grooved side of the belt for cracks. A crack approximately every three inches is not a problem, but cracks every one to two inches mean the belt must be replaced. Cracks that run parallel to the belt's "V" portions are also bad. You should also replace the belt if its edges are fraying, or if it has been contaminated by oil, antifreeze or other fluid. To figure out the type of belt you need to replace the old one with, use your car's vehicle identification number on the dashboard. Use this number at the auto supply shop so the dealer can determine the belt your vehicle needs.
  
  

Replacement

• Remove the belt by loosening the tension on the belt's tensioner. Turn the bolt on the front of the tensioner to loosen it. This can often be done with a breaker bar and socket, but some vehicles may not have enough room for that in the engine compartment; in that case, use a specific drivebelt tool from the auto supply store. You usually need to turn the bolt counter-clockwise, but this can vary depending on the vehicle. Once the tension is relieved, slip the belt off its pulleys, making sure you know exactly how it was looped around those pulleys. Install the new belt in the exact same path that the old belt was routed, making sure the belt completely fits into the pulley grooves. Rotate the tensioner in the opposite direction from before; the tensioner must be tightened at a specific torque. Check a repair guide for your vehicle to find its required torque.