Car Parts Basics: the Serpentine Belt | Allstate Insurance

Hey everybody, it’s Charles from
and today we are talking serpentine belts. The serpentine belt is a vital component on
most vehicles and it has the incredibly important task of driving engine accessories. The most common accessories driven by the
serpentine belt are going to be the alternator the power steering pump and the AC compressor. Some engines may also drive other accessories
like the water pump. On most vehicles, a pulley on the end of the
crankshaft is what turns the belt and drives the accessories. The system also consists of a tensioner to
keep the belt tight and maybe even additional rollers to help guide the belt. These are commonly referred to as idler pulleys. Maintenance intervals vary depending on the
belt and the vehicle but typically range anywhere from 60 to 100,000 miles. It’s really important to perform periodic
inspections on your serpentine belt. Let’s start with a visual inspection. What you’ll be looking for is: cracks across
the ribs of the belt; if the belt has a non-ribbed side; perhaps any glazing or really shiny
spots; or any other signs of belt damage including the edges of the belt frame. Another way to inspect the belt is to use
a serpentine belt rib tool. This is actually the best way to check for
belt wear. As the belt wears into a pulley, the depth
of the ribs become even deeper. This is a normal condition, but it may be
really hard to see. Using a tool like this, that can be purchased
at most auto parts stores, is really the best way to inspect the belt. When you set this tool on the ribbed portion
of the belt, it can show how much wear the belt has on it. Also, any oil or coolant saturation on the
belt means it’s time to replace it and fix those leaks. In addition to normal wear and tear, we also
want to be aware of some types of failures. A complete failure of a serpentine belt is
when the belt breaks or comes off the rollers. This means the accessories are not being driven
and may result in no charging voltage, no AC or no power steering, and in certain cases
can lead to vehicles overheating. We also may encounter some noise, like a squeak
noise, when a serpentine belt’s worn out. Not only is it common when the belt wears
but this can also be the sign of a failing tensioner or a failing bearing in any one
of the pulleys. When it comes to replacement of a serpentine
belt, it’s usually pretty straightforward and requires very simple, basic hand tools. Most of the time, the biggest challenge is
actually getting to the belt itself. When you’re doing the belt, draw out the pattern
of the belt on a piece of paper or take a picture with your phone to help remind you
of the routing of the belt. If you guys have any serpentine belt questions
or comments, feel free to leave them down below. If you want to check out more of my videos
head over to Alright guys, thank you guys so much for watching,
and I’ll see you next time.


my car grinds when I push on the brakes. I had the rotors and pads replaced, one auto repair shop said it might be the "R&R Serpentine Belt Tensioner". Does this sound right to you? It is a 2002 Toyota Camry. Thanks

I have a kia Optima 14 the pulley on the top wore out, im not sure if thats a the alternator or water pump. Do i have to change the belt as well?

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