How to Replace Your Car’s Serpentine Belt

Doesn’t a serpentine belt sound cool? All scaly and serpentine. Well, it’s not without reason called that. This long belt in your vehicle’s engine has vertical grooves along its length and wraps around multiple pulleys, linking them to the crankshaft’s action. As it rotates, the belt moves the pulleys, which in turn powers many automotive accessories, including the alternator, air conditioning compressor, power steering pump, and occasionally the water pump.

Earlier automobiles featured separate belts for each of these systems. They wore out quicker, and simply having more belts meant they occupied more room. A single serpentine belt is lighter and produces an engine that is more compact and efficient.

But it also necessitates threading a needle.

Serpentine Belt Prep Work

How to Replace Your Car's Serpentine Belt

To replace a serpentine belt, you will need simply a replacement belt, a belt tensioner tool, and possibly a socket wrench. These items should be readily available at car parts stores. Gloves and eye protection are also beneficial.

Every automobile engine is unique, even those from the same automaker. Consequently, the serpentine belt will wrap the pulleys in a different order. In order to view what’s going on with the belt on a newer vehicle, you may need to remove a plastic cover from the engine. When the engine has cooled, open the hood and orient yourself.

A few suggestions for situating the replacement correctly:

  • Check the owner’s handbook of your vehicle for a diagram of the serpentine belt.
  • Also search online for belt schematics. (We discovered many)
  • Take numerous photographs of your engine from various angles using your smartphone.
  • Under the hood, there may even be a belt winding diagram.

You will need to refer to these while removing the old belt and installing the new one.

Removing the Old Belt

How to Replace Your Car's Serpentine Belt

After noting the placement of the belt, it is time to remove the old belt.

Find the belt tensioner first. It prevents the belt from becoming excessively loose, which would allow it to slip. It typically has a square-shaped hole through which the belt tensioner tool fits. This is the most prevalent type of belt tensioner found in modern automobiles, but some vehicles employ only a socket-adjustable bolt.

When the serpentine belt has some slack, it can be carefully removed from the pulleys. You will likely observe one pulley rubbing on the belt’s smooth back. This represents the idler pulley. It does not provide electricity, but it helps keep the belt in place.

Now is the time to perform some maintenance. Using a wire brush, you can remove old rubber fragments and dust from the grooves where the belt sits on the pulleys. Additionally, you can inspect the belt for wear. Most belts must be replaced over time, so inspect for cracks, fraying, or glossy areas (known as glazing) caused by misalignment or other problems.

Also inspect the pulleys for oil, as this may indicate a leak. In addition to being bad for the engine, oil can deteriorate rubber, requiring you to repeat this process sooner rather than later.

Installing the New Belt

How to Replace Your Car's Serpentine Belt

Now is when you will appreciate having diagrams and photographs. Reinstall the belt onto the vehicle’s pulleys in the correct sequence.

Remember that every pulley with grooves is intended to be driven by the serpentine belt’s grooves. The idler pulley, for instance, lacks grooves because it rests on the reverse side of the belt. Nonetheless, the power steering pump pulley has grooves. To turn these accessories with the power of the crankshaft, you must literally break a sweat.

Hold the belt tensioner loose while threading the final pulley. When everything is in position and the grooves are seated, use your belt tensioner tool or socket to tighten the tensioner pulley.

It is now time to give it a shot. Gentlereaders, ignite your motors! Run it for a minute or two to ensure that everything is in place and functioning properly.

How Often Does a Serpentine Belt Need to Be Changed?

Belts made of serpentine can survive a long period. Manufacturers typically advise replacing them at 60,000 miles (96,560 kilometers), while other guidelines suggest going as far as 100,000 miles (160,934 kilometers). The key is to replace them prior to their failure.

It may not be too horrible to travel without air conditioning, but the alternator charges your car’s battery and electrical system, and driving without power steering will be a workout.

Here are a few indications that your serpentine belt may have reached its end:

  • You hear a loud squealing, particularly while turning the steering wheel to the extreme left or right. This is the most prevalent sign that people observe.
  • The dashboard battery indicator illuminates if the alternator is not receiving electricity.
  • If the belt is meant to be operating the water pump, the dashboard temperature indicator illuminates.
  • The check engine light is illuminated.
  • The steering feels slow or heavier than usual.

A serpentine belt is difficult to install, despite the fact that this is neither an expensive nor tremendously difficult repair. It is useful to understand what this belt is and what it performs, but engine repairs are sometimes better left to the experts. Your mileage may vary depending on your knowledge and confidence, as the saying goes.

Scroll to Top