How a Toyota’s Serpentine Belt Works

August 4th, 2017 by

When you fire up your engine, it starts up. You drive away, just trusting that your car is going to work flawlessly. Behind the scenes, there is a whole bunch going on. And keeping your car’s accessories functioning is the role of a thin rubber belt known as a serpentine belt. But what does it do?

What a Serpentine Belt Does

Not that long ago, most cars used multiple belts on the engine to keep everything working. There would be a single belt used to turn the power steering pump, one to turn the air conditioning compressor – if you had air conditioning, that is -, and one for the alternator.

As more functions and options were added, more belts were used. It got pretty busy under the hood. Then, the serpentine belt was introduced. It was one wider belt that could be used to turn most or all of the systems attached to the engine. It simplified the engine bay and added reliability.

What Is a Serpentine Belt?

The serpentine belt itself is a drive belt that is wide and flat. It has several ribs on one side while the other side is flat. The ribbed side engages into pulleys and provides the grip necessary to turn all the engine’s accessory systems at once.

It’s made of synthetic rubber that’s been reinforced by strands of fabric, and sometimes even kevlar to make it stronger.

Can It Fail?

A serpentine belt will eventually need to be replaced. The rubber begins to deteriorate over time, the belt stretches, and the ribs begin to crack. Like any other belt, it should be changed before any problems occur. Should the belt break, it can leave you in a tough spot, with a broken-down car, or in a dangerous driving condition.


Luckily, your serpentine belt is inspected every time your car is serviced at Jay Wolfe Toyota of West County. We’ll check its condition to ensure it’s safe to use for the foreseeable future. If your belt needs to be replaced, our factory-trained Toyota technicians will get it done for you right away, and at a reasonable cost.


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