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Serpentine Belt Replacement: Step-By-Step Guide (+FAQs)

October 16, 2021

Serpentine belts usually last a long time.
But if this belt breaks, it can bring your engine to a standstill immediately. 

In this case, the only solution is to get a serpentine belt replacement.
But how do you go about replacing a worn serpentine belt? 

In this article, we’ll give you a step-by-step breakdown of the serpentine belt replacement process and cover some common serpentine belt questions.

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Let’s begin.

How To Perform A Serpentine Belt Replacement 

Performing a serpentine belt replacement on your own isn’t impossible if you have the right tools and technical know-how. 

However, if you aren’t sure how to do the belt replacement yourself, it’s best to call a serpentine belt replacement service where an ASE-certified mechanic can do the job for you.

If you do have the tools and knowledge, here’s what you need to do to replace a worn serpentine belt: 

To begin with, a serpentine belt replacement needs: 

Here’re the details on the serpentine belt replacement process: 

Step 1: Note The Placement Of The Belt 

The belt path a serpentine belt weaves through is unique to each car. 

To note down the fan belt placement: 

Step 2: Examine The Tensioner 

Before removing the worn serpentine belt, the mechanic will check the belt tensioner for any excess vibration. The tensioner pulley is what maintains the belt tension around the pulleys for engine accessories. 

A well-functioning tensioner should have a slight vibration. A properly tensioned belt should also run smoothly around the tensioner with no visible vibration. 

If the pulley exhibits a jerky vibration, the belt vibrates, or if the tensioner arm moves more than ¼ inch, it’s a symptom of a faulty belt tensioner. 

Step 3: Loosen And Unthread The Belt

To remove the serpentine belt, your mechanic needs to loosen the tensioner pulley first.

Here’s how:

Step 4: Check For Belt Damage

After removing the old belt, the mechanic will do a visual inspection for any signs of damage. They’ll look for any disintegration along the edges. Separated belt grooves or ribs also indicate a misaligned serpentine belt.

If the drive belt of your car has multiple cracks on adjacent belt ribs within an inch or has more than four cracks per inch on a single rib, you’ll need a belt replacement. 

Other warning signs of a bad serpentine belt include missing chunks from the belt ribs, frayed fan belt fabric, glazing on the belt’s back, or debris between the belt teeth or ribs. 

Step 5: Examine Each Pulley

Your car mechanic will use a straightedge tool to ensure that every pulley is aligned correctly. They’ll give the idler pulley and the tensioner pulley (automatic belt tensioner) a good spin to ensure that these move freely without any unusual noise.

If any idler pulley or other pulleys fail, your car’s serpentine belt can fall off and stop the power steering pump and water pump in the cooling system. The alternator and air conditioning compressor will also stop running. 

Also, the mechanic may ensure that there are no oil leaks as they can result in a worn belt. They’ll brush off dirt or grime around each pulley to prevent any further misalignment, too. 

Step 6: Install The New Belt 

Here’s how the mechanic will install the new serpentine belt in your car:

Serpentine belts are pretty inexpensive and have a long belt life

And if you think you have a possible belt failure, don’t hesitate to get a new one. A serpentine belt replacement is an essential part of overall car maintenance and can cost anywhere from $70-$200. 

If you plan to do it yourself, make sure you install the belt correctly, or you can end up harming the engine processes. Otherwise, it’s always best to have auto service professionals perform the serpentine belt replacement for you. 

Now that we have the basic steps covered, let’s go over some common questions about serpentine belt replacement. 

5 Serpentine Belt Replacement FAQs

Here’re the answers to five belt replacement FAQs. 

1. When Do I Need A Serpentine Belt Replacement?

A fully functioning belt drives multiple engine processes. These include the alternator, power steering pump, air conditioner, cooling fan, and water pump. 

Today, belt manufacturers make these belts with a special synthetic rubber called EPDM (Ethylene Propylene Diene Monomer). This serpentine belt material usually results in long belt life. 

Under ideal conditions, a drive belt can last 60,000 to 100,000 miles. 
You can also go for a belt replacement as a part of your overall car maintenance. 

However, if you have serpentine belt issues like a loose belt, it can end up shutting down all of the engine processes, and your engine itself can get damaged from overheating. 

If you notice any of the following signs, schedule an appointment for serpentine belt maintenance and possibly have it replaced: 

A. Squealing From Power Steering Or Air Conditioning:

The drive belt controls engine accessories such as power steering, air conditioning compressor, water pump, etc. It takes a lot of torque for the belt to turn the respective pulleys. 

If you get a squealing sound when you turn the air conditioner on or while turning the steering wheel of your car, you may have a belt failure or a worn belt. 

B. Visible Wear And Tear Of The Belt

If you notice any belt wear and tear like cracks, frayed ends, missing ribs, or damage while conducting regular inspections or during overall car maintenance, it’s time for a new serpentine belt. 

C. Poor Air Conditioning

A worn belt can reduce the power supplied to the air conditioning compressor as it limits the motion generated by the engine crankshaft. 

If you feel that the air conditioner isn’t offering optimum cooling, get your car’s drive belt checked. 

D. No Power Steering

The loss of power steering can also result from a faulty serpentine belt. 

Though there could also be other steering issues like lack of power steering fluid or broken power steering pump, it’s best to get the cause ascertained by a mechanic. 

E. Battery Warning Light

The serpentine belt also powers your car’s alternator pulley, which provides electrical power to the battery while the engine is running. If you notice an illuminated battery light, it means that the battery isn’t charging, and there’s a bad alternator or a possible belt failure. 

F. Squealing Noise Under The Hood 

A squealing engine noise means that there’s a belt slippage. Sometimes the bearing of the tensioner pulley can wear out and reduce the belt tension. 

In such a case, a new serpentine belt isn’t required. Fixing the bearings should resolve the issue. 

2. What Happens When The Serpentine Belt Breaks?

When a car’s serpentine belt breaks, the engine accessories stop functioning. 

These include the steering pump, air conditioning compressor, cooling fan,  alternator, and water pump. 

The first sign of a possible belt failure is the lack of power steering. Also, check the battery light. The battery light glows up as the alternator stops functioning. 

Most importantly, your engine might suffer from overheating within minutes, as the water pump also stops working. When you notice any of these symptoms, pull over immediately and call for roadside assistance

3. Can I Drive My Vehicle With A Bad Serpentine Belt?

It’s not recommended to drive your vehicle with a faulty serpentine belt as serpentine belt issues can turn up suddenly. The belt can even roll around the engine compartment and damage some vital systems of your car. 

If you have a broken belt, you can end up with a dead battery which results in your car not starting. Since a broken serpentine belt can’t run the cooling fan or the water pump, it will result in rapid engine overheating. 

If you don’t get a serpentine belt service soon, your engine will self-destruct in no time. 

4. Are Serpentine Belt And Timing Belt The Same? 

A serpentine belt is also known as an accessory belt, drive belt, or fan belt. 
It is not the same as the timing belt.

A timing belt is located inside the engine of your car. It keeps the crankshaft and the camshaft in sync so that the engine can run smoothly. 

On the other hand, a car’s serpentine belt or the drive belt is located outside the engine and keeps the engine accessories like steering, air conditioner, etc., running. 

Another difference between a timing belt and a serpentine belt is that a timing belt has horizontal “teeth” to fit into the cogwheels of the crankshaft. In contrast, the other has v-shaped grooves running vertically along the belt. 

5. What Should I Do If My Serpentine Belt Is Worn Out?

In case of a loose belt or a faulty serpentine belt, you can: 

If you’ve got a broken serpentine belt, your engine will cease to function.
So, instead of towing your car to a repair shop, take the help of a mobile serpentine belt replacement service like RepairSmith

With RepairSmith, you get:

For an accurate estimate of how much your fully functioning belt will cost, just fill this form

Closing Thoughts

If your car makes an unusual noise or the engine accessories stop working optimally, it could indicate serpentine belt issues. 

When this happens, consider getting a replacement because the earlier you address the problem, the lower the belt replacement cost might be.

And if you need a certified serpentine belt replacement service to install a fully functioning belt, just contact RepairSmith. They’ll send you an ASE-certified mobile mechanic to run a basic fan belt maintenance or to replace your broken serpentine belt right in your driveway!