When a vehicle owner needs a replacement belt or hose, it's rarely a planned transaction. Motors who only need a belt or hose have likely experienced an unexpected breakdown. While that might be tempting for your DIFM customer to replace the failed part and quickly send the customer on their way, it's a prime opportunity for counter professionals to encourage shops to take a system approach D parts replacement. Let's talk about the serpentine belt. Most vehicle owners know that a noisy belt means something might be wrong, but they probably don't know that replacing the belt rarely stops the noise on its own. That's because the serpentine belt is part of a system of interrelated parts that all need to be in working order for the system to function properly. The serpentine belt, also known as the accessory belt, drives the alternator, that power steering pump, the air conditioning compressor, and sometimes the water pump via the crank shaft.