Car Fan Belt Functions, Features, and How to Replace a Car Fan Belt

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Fan Belt Mobil

A car fan belt, also known as a serpentine belt or drive belt, is a rubber belt used in vehicle engines to drive various engine components such as radiator fans, generators, water pumps, and other components. Its purpose is to transmit power from the engine’s crankshaft to the various components that require that power.

In general, fan belts are made of rubber reinforced with fiber or steel fibers to provide the necessary strength and durability to cope with the stresses and loads encountered during operation. These belts rotate around pulleys or gears on different engine components, thus moving them and ensuring that the various vehicle systems function properly.

If the fan belt is damaged or broken, the components that depend on the movement of the belt will not function properly. Therefore, it is important to regularly check the state of the fan belt and replace it if signs of wear or damage are found. Proper maintenance of the fan belt can help prevent bigger problems with the vehicle’s engine system. Read through this article TransTRACK for a more complete explanation!

Fan Belt Function in Cars

Fan belts, also known as drive belts or serpentine belts, have several important functions in cars. The main function of the fan belt is to drive various engine components that are required to run vital systems in the vehicle. Some of the main functions of the fan belt involve moving the following components:

Radiator Fan

The fan belt is used to drive the radiator fan. This fan helps cool the coolant flowing through the radiator, keeping the engine temperature within safe limits.

Generator (Alternator)

The fan belt transmits power from the engine crankshaft to the generator. The generator generates the electricity needed to charge the battery and provides electrical power to the various electronic components in the car.

Water Pump

The fan belt also drives the water pump, which is responsible for circulating coolant through the engine’s cooling system. This helps to keep the engine temperature within safe limits.

Power Steering Pump

In some vehicles, the fan belt is used to drive the power steering pump, which allows the driver to control the steering wheel more easily.

Air Conditioning Compressor

If the car is equipped with an air conditioning (AC) system, the fan belt can be used to drive the AC compressor, which compresses refrigerant to produce cold air.

Hydraulic Pump

In some vehicles, the fan belt can be used to drive a hydraulic pump that supports various hydraulic systems in the car.

Its function in driving these various components makes the fan belt one of the key components in maintaining the performance and function of the car engine. Therefore, good maintenance of the fan belt is very important to prevent potential damage and more serious engine problems.

How to Check the Fan Belt

Checking the fan belt regularly is an important part of maintaining your vehicle. Here’s how to check the condition of the fan belt:

Turn off the engine

Make sure your vehicle’s engine is turned off and the ignition key is in the off position before starting the inspection.

Locate the Fan Belt

Identify the location of the fan belt inside your vehicle’s engine. Typically, the fan belt is located around the pulleys at the front of the engine and is connected to several components such as the radiator fan, generator, and water pump.

Check Tension

Touch the fan belt and press gently. The fan belt should not be too loose or too tight. Proper tension is important for good performance. If it is too loose, it may need to be pulled tighter or it may be time for a replacement.

Check for Wear or Cracks

Visually inspect the fan belt to see if there are any signs of wear, cracks, or other damage. If you see cracks or small missing pieces, this could be a sign that the fan belt needs to be replaced.

Look for Dirt or Oil

See if there are signs of dirt, dust, or oil on the fan belt. Excessive dirt or oil can cause slippage and reduced performance.

Check Each Side of the Fan Belt

Some fan belts have two sides that can be used. Check both sides to ensure they are in good condition.

Check the Pulleys

Check the pulleys or gears driven by the fan belt. Make sure that the pulleys have no damage or significant wear.

Checking with the Engine Running (For Some Models Only)

On some vehicles, you can check the fan belt while the engine is running. However, do this carefully and avoid rotating parts. Do not touch the fan belt directly while the engine is running.

If you notice signs of wear, improper tension, or other damage, the fan belt should be replaced immediately. Checking the fan belt regularly is an important preventive measure to prevent further damage and ensure good performance of the components driven by the fan belt.

Characteristics of a Car Fan Belt Needs to Be Replaced

There are several characteristics that indicate that the fan belt in your car may need to be replaced. If you notice one or more of the following signs, it’s best to check the fan belt immediately and consider replacing it:

Squeaking or Creaking Sounds

If you hear a squeaking or creaking sound when the engine is running, this could be a sign that the fan belt is experiencing excessive wear or friction. The noise may appear when the fan belt starts to slip or doesn’t move smoothly around the pulleys.

Excessive Tension or Too Loose

If the fan belt is too tight or too loose, it could be a sign of trouble. Excessive tension can lead to faster wear and tear, while too much slack tension can cause slippage and decreased performance.

Physical Signs of Damage

Visually inspect the fan belt to see if there are any physical signs of damage such as cracks, cuts, or significant wear. If you see these signs, the fan belt may need to be replaced immediately.

Increased Fuel Usage

While this is not always the case, increased fuel consumption can be an indication that the fan belt is not functioning efficiently. This is because a worn or slipped fan belt can cause components such as the generator to work harder and result in increased fuel consumption.

Radiator Fan Not Rotating Well

If the radiator fan is not spinning properly, it could be due to a problem with the fan belt. This check can be done while the engine is off.

Indication of Low Voltage

If the battery indicator light on the dashboard is on, or if you see signs of low voltage, it could be that the fan belt that drives the generator is not functioning properly.

Excessive Heat

A fan belt that is not functioning properly can cause an increase in engine temperature. If you notice an unnatural increase in temperature, check the fan belt as part of troubleshooting.

It is important to remember that a worn or damaged fan belt can cause further damage to other components in the drive system. Therefore, if you suspect a problem with the fan belt based on the above characteristics, immediately conduct further inspection and replace the fan belt if necessary. Good maintenance can prevent more serious problems with your vehicle.

How to Replace a Fan Belt

Replacing a fan belt on a car can be a relatively simple task, but it requires some basic tools and an understanding of the basic structure of your vehicle’s engine. Here is a general guide to replacing a fan belt:

Tools Required

  • Wrench or ring wrench set.
  • Adjustable wrench.
  • Socket and handle wrench (ratchet).
  • Fan belt setting diagram for your vehicle (usually found on the hood or in the vehicle manual).


  1. Turn off the engine:

Make sure the vehicle engine is off and the ignition key is in the off position.

  1. Fan Belt Location:

Identify the location of the fan belt in the engine. Check if there is a fan belt setting diagram available on the hood or your vehicle manual.

  1. Disconnect the Battery:

For added safety, disconnect the positive terminal of the battery to avoid accidental electrical contact.

  1. Remove Components that Obstruct Access:

If necessary, remove any components that may be blocking access to the fan belt, such as fans, engine covers, or other components.

  1. Release the Fan Belt Tension:

Use a wrench or ring wrench set to loosen the fan belt tension. Some vehicles have an adjustable component to adjust the fan belt tension. Turn the adjuster bolt to reduce the tension.

  1. Remove the Old Fan Belt:

Once the voltage has been reduced, remove the fan belt from the pulleys it is connected to. Pay close attention to the way the fan belt passes through the pulleys so that you can install the new one correctly.

  1. Installation of the New Fan Belt:

Place the new fan belt on the pulleys by following the correct route according to the fan belt arrangement diagram. Ensure that the fan belt is correctly placed on each pulley.

  1. Adjust Fan Belt Tension:

Use a wrench or ring wrench set to adjust the fan belt tension. Make sure the tension is in line with the manufacturer’s recommendations.

  1. Double Check All Installations:

Make sure all previously removed parts are reassembled correctly. Make sure the fan belt is seated properly on the pulleys and is not too loose or too tight.

  1. Reconnect the Battery:

Reconnect the positive terminal of the battery.

  1. Check Performance:

Start the engine and check if the fan belt is rotating properly on the pulleys and if the previously heard squeaking or rubbing sound has disappeared.

  1. Check the Return Voltage:

Ensure that the fan belt tension remains appropriate after starting the engine. Adjust if necessary.

If you are unsure or uncomfortable doing the fan belt replacement yourself, it is recommended to get help from an experienced mechanic or automotive technician. Improper fan belt replacement can cause further damage to the vehicle’s engine.

In maintaining optimal vehicle health and performance, fan belts are an important element that should not be overlooked. By adopting TransTRACK’s  Vehicle Maintenance System, you open the door to smart and efficient maintenance monitoring.

TransTRACK makes it easy to plan, track, and maintain maintenance schedules for fan belts and other components. Automatic notifications, breakdown prediction, and better cost management are some of the benefits you can enjoy.

Take care of your vehicle investment with TransTRACK. By visiting our website, you can unlock a world of planned and time-saving vehicle maintenance. With TransTRACK, you not only keep your vehicle running, but also provide the best protection and care for every journey.


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