How to Replace an Air Conditioning Belt

Unless you drive a newfangled hybrid or electric car, the AC compressor in your vehicle is driven off a belt. The belt is strapped to the engine crankshaft balancer, which turns with the engine. Older vehicles use v-belts, which typically only drive the AC compressor. Modern vehicles use serpentine belts to drive all of the engine accessories including the drive belt.

Over time, belts crack and deteriorate. Replacing the belt at the first sign of wear ensures it won’t break, leaving you without AC.

Part 1 of 3: Determine which type of belt you have

Materials Needed

  • Jack
  • Jack stands

How to Replace an Air Conditioning Belt 2

Step 1: Locate the AC belt. The AC belt is routed over the AC compressor, which is located at the front of the engine compartment.

You may need to raise the vehicle with a jack and support it with jack stands for access.

How to Replace an Air Conditioning Belt 3

Step 2: Determine which type of belt you have. Determine which type of belt you have.

V-belts will be thin with a single rib. Serpentine belts will be multi-ribbed and much thicker.

Part 2 of 3: Remove and replace the serpentine belt

Materials Needed

  • Protective gloves
  • Repair manuals
  • Safety glasses

  • Tip: You can often get free repair manuals for your car.

How to Replace an Air Conditioning Belt 4

Step 1: Locate the serpentine belt tensioner. If you have a difficult time finding the tensioner, consult the belt routing diagram.

This can typically be found on a decal placed somewhere in the engine compartment or in the vehicle repair manual.

How to Replace an Air Conditioning Belt 5

Step 2: Rotate the tensioner. Use a socket or wrench to slide the automatic tensioner away from the belt.

Whether this is clockwise or counterclockwise depends on the vehicle and belt routing.

  • Note: Some tensioners will have a square hole to insert a ratchet end into rather than a bolt head for a socket or wrench.

How to Replace an Air Conditioning Belt 6

Step 3: Remove the belt from the pulleys. While holding the tensioner away from the belt, slide the belt off the pulleys.

How to Replace an Air Conditioning Belt 7

Step 4: Position the belt on the pulleys. Position the belt on the pulleys.

Following the belt routing diagram to ensure the belt is routed correctly.

How to Replace an Air Conditioning Belt 8

Step 5: Install the new belt. Push or pull the tensioner to a position that allows the belt to be installed onto the pulleys.

Once the belt is in place, you can release the tensioner and remove your tool.

Part 3 of 3: Remove and replace the v-belt belt

How to Replace an Air Conditioning Belt 9

Step 1: Locate and loosen the compressor pivot. The compressor on older vehicles will generally have a pivot bracket.

Loosen and/or remove the pivot bolts. Then, push the compressor away from the belt.

How to Replace an Air Conditioning Belt 10

  • Note: Some compressors use an idler wheel tensioner. In this case, instead of loosening pivot bolts, you’ll loosen the locknut on the idler adjusting screw. Then, turn the adjuster until the belt is loose enough to be removed.

How to Replace an Air Conditioning Belt 11

Step 2: Remove the belt. Remove the belt by sliding it off of the pulleys.

How to Replace an Air Conditioning Belt 12

Step 3: Install the new belt. Install the new belt by correctly positioning it in the pulley grooves.

How to Replace an Air Conditioning Belt 13

Step 4: Adjust the belt. Push the compressor back into its original position so that the pivot bolts and holes line up.

Put enough pressure on the compressor so that the belt is snug but not too tight. In order to achieve this, you may need to use a pry bar to put tension on the compressor and hold it in place while you tighten down the pivot bolts.

  • Note: If your compressor uses an idler wheel tensioner, tighten the belt until it's snug using the adjuster, then tighten down the locknut.

How to Replace an Air Conditioning Belt 14

Step 5: Check the belt tension. Once the new belt is installed, you’ll want to check the belt tension.

To do that, push down on the longest length of the belt - there should be about ½” of deflection. If not, loosen the belt and readjust as outlined in the previous step.

That’s it! Now you don’t have to worry about losing your AC on a hot day due to a failed belt. You can crank the AC up and enjoy. If, after reading this, replacing your belt sounds like something you’d rather leave to the pros, let the team at YourMechanic perform a replacement for you.


Next Step

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Recent Serpentine/Drive Belt Replacement reviews

Excellent Rating

(4,506)

Rating Summary
4,307
113
22
16
48
4,307
113
22
16
48

Christopher

10 years of experience
70 reviews
Christopher
10 years of experience
Toyota Corolla - Serpentine/Drive Belt - Cypress, Texas
Christopher was here for about 2 hours and he did quite a bit of work. The worksite was left clean, which was much to my liking. He had to change out the transmission oil and engine oil in my Mother's car. Who would have known that you could have this done in your own garage, with no mess or hassle.
Jeep Wrangler - Serpentine/Drive Belt - Katy, Texas
Chris really went out of his way to get my Jeep back on the road. He had to order a part and even though the scheduling system had me waiting almost a week for him to return, he actually showed up the next day! Great service, great communication!

Jonathan

26 years of experience
24 reviews
Jonathan
26 years of experience
Hyundai Sonata - Serpentine/Drive Belt - Marietta, Georgia
Ward showed up on time and completed an overly complicated (Due to design and engine room workspace) drive belt swap out on my Hyundai Sonata in a reasonable amount of time.He answered all questions I had well,even about auto repair issues not necessarily related to the drive belt.Thanks to Ward and his young son helper for coming out in the early evening darkness (Equipped with headband flashlight) to do this job.
Hyundai Genesis - Serpentine/Drive Belt - Roswell, Georgia
Diagnose the problem and came back the next day to replaced my alternator. I did not have to leave the house.

Adam

17 years of experience
79 reviews
Adam
17 years of experience
Jeep Wrangler - Serpentine/Drive Belt - West Palm Beach, Florida
Adam was knowledgeable, courteous, and professional. The overheating issue w/ my Jeep has been corrected.
Mitsubishi Eclipse - Serpentine/Drive Belt - Boca Raton, Florida
Excellent mechanic. Goes the extra mile to make sure you are satisfied. Very knowledgeable in his craft.

Michael

4 years of experience
99 reviews
Michael
4 years of experience
Volkswagen Golf - Serpentine/Drive Belt - Indianapolis, Indiana
Very communicative, super pleasant and professional. Was running late on a previous job through no fault of his own and let me know well in advance of my appointment time. Extremely courteous. 10/10 would recommend and hire again.
Chevrolet Avalanche - Serpentine/Drive Belt - Carmel, Indiana
Michael is always professional, knows what he is doing and very nice. I would recommend him to anyone that needs repairs.

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