Replace a Serpentine Belt Task

Click here to download the teacher resource for "Replace a Serpentine Belt Task."

Course: Maintenance and Light Repair I (MLR I)

Task Length: 1 Hour

Replace a Serpentine Belt

Task Description


Students will:

  • Read the linked materials
  • Watch the linked videos using guided notes
  • Record a video of themselves describing the steps and tools involved in replacing a serpentine belt.

Safety Note: If possible, students should do this task with a vehicle, but ensure the students do so safely. Lifting the vehicle is not required for the purpose of the student video.

Inspect, replace, and adjust drive belts, tensioners, and pulleys; check pulley and belt alignment. (6.9)

Overall Standard (6): Students will perform basic vehicle engine service and maintenance.

 Content Understandings

Extending Understandings

Upon successful completion of these tasks students will demonstrate the ability to:

  • Explain why a serpentine belt must be replaced.
  • Select the tools required.
  • Describe required safety precautions.
  • Locate the serpentine belt.
  • Describe how to inspect a serpentine belt.
  • Explain why the serpentine belt must be routed properly.
  • Describe how they will remember the correct way to route the new serpentine belt.
  • Explain why there is tension on the serpentine belt.
  • Locate the tensioner.
  • Describe the order of the steps to remove the serpentine belt.
  • Describe how to reduce tension on the tensioner. 

To move students towards deeper understanding, they should be given opportunities to:

  • Describe what may happen if the serpentine belt breaks.
  • Explain how a bad tensioner can cause premature wear in a serpentine belt.
  • Describe what to do to replace a serpentine belt if a tensioner is not used in a vehicle.


Support Strategies

If students are struggling to access this task, additional supports and strategies could be employed as students are engaging with the task.

Key Terms

Sentence Frames

Scaffolded Questions


The ______________ applies pressure to the serpentine belt to ensure it stays in place.

How does the tensioner hold the serpentine in place?

Should the tensioner spin freely?

Instructional Resources

Materials to read (see student/teacher guide below)

Tire Review (2015, Jan 8). ASE G1: Drive Belt Inspection, Replacement

Wiki How (2019, Sep 6). How to Replace a Serpentine Belt


Videos to watch (see note guide below)

Note: The videos have different model vehicles.

1A Auto (2011, Nov 23). How to Replace Serpentine Belt 02-09 Chevy Trailblazer (Video). YouTube. (5 minutes)

The Humble Mechanic (2017, Dec 31). How to Replace a Serpentine Belt (Video). YouTube. (6:30 minutes)

1A Auto (2019, Jun 4). How to Replace Serpentine Belts 09-14 Ford F150 (Video). YouTube. (12:30 minutes)

Student Resources

Click here to download the Reading Guide and Video Guide for this task. 


Replace a Serpentine Belt


Student Reading Guide


  1. What may happen if the serpentine belt is not replaced?




  1. What are possible signs that a serpentine belt needs to be replaced?




  1. What parts of the engine are possibly connected by the serpentine belt (depending on vehicle)?




  1. What safety precautions are required while replacing a serpentine belt?




  1. What tools and parts are needed?



Student Video Guide


  1. Locate the ______________________________. Depending on the vehicle, the serpentine belt may be located in the front or along the side of the engine. Normally it can accessed from above. There may be engine covers that need to be removed before the belt can be replaced.  Engine covers are held in place by plastic clips. Be sure to not break the plastic clips while removing the cover. A few vehicles need to remove other parts to replace the serpentine belt.


  1. Find the belt routing diagram.  It will either be on the engine or in the owner’s manual.


  1. Look at the way the old belt is routed around the _____________.  Be sure to understand how the belt wraps around the pulleys and tensioner.  Take a photo to be sure.


  1. Determine if there is a _________________________________ – which is most common. If not, the alternator bracket is likely the way tension is set on the belt.


  1. If there is a tensioner - Use the wrench or special removal tool on the tensioner to release the ___________ on the old belt.  Tensioners either have a hole that fits a common drive ratchet or a bolt to be twisted.  Twist the tensioner away from the belt to relieve the tension so the belt can be removed.


  1. If there is no ___________________ – Use a wrench to loosen the bolts on the alternator bracket.  As the bolts are loosened the tension will be reduced enough to remove the old belt.  Do not remove the bolts.


  1. Pull the belt off the pulleys.


  1. While the _________ is off look at the tensioner and pulleys to see if they are operating properly.


  1. Verify the new belt is the correct size by comparing it to the old one. Verify the length and _______ are the same. Verify the number of ribs on the belts are the same.


  1. Install the new belt.  Be sure to ________ it the same way as the old one. Refer to the belt diagram or photo to be sure.


  1. Apply pressure with the ________________ and put the belt over it. Use the same wrench that was used to loosen the tensioner.


  1. If there is no tensioner – Use a pry bar to pry the alternator away from the engine and increase tension on the belt.  Tighten the bolts on the alternator bracket as the tension is applied.  This may require a second person to help.


  1. Verify that the new ______________________________ is properly installed.