The core of any air conditioning system is the compressor. In short, the compressor compresses the refrigerant vapour, which starts the process of exchanging heat through the use of the refrigerant’s thermodynamic properties.
Refrigerant acts as both a liquid and a gas throughout the AC system. Through the various components in the AC system, the refrigerant goes through the transition from a gas to a liquid and from a liquid back to a gas. This transition is what causes cold air to come out of your vents.
Cost to Replace Car AC Compressor
The labour rates and the location of the service can greatly affect the cost, as well as the make and model of the vehicle. Expect to pay almost double if you’re servicing a German car.
In order to service an AC compressor, the vehicle must also have an evacuation and recharge performed. The refrigerant must first be removed so that the compressor can be replaced, and then the refrigerant must be recharged back into the system.
This is an additional cost that must be added to the completed replacement cost. This can range from £85 to £175 depending on where you are servicing your vehicle. Some places may just roll this cost directly into the repair and not even tell you, as you must perform this service first anyway.
At most independent repair facilities, the labour rate will be much lower than at the dealership, and parts costs will also be much lower. Assume that the independent shop has a labour rate of £70 per hour and all parts are aftermarket.
Most independent shops will replace the entire compressor as most aftermarket parts suppliers do not make just clutch or coil replacement parts. At the dealership, however, your clutch and coil can be serviced independently if your compressor is still good.
On an everyday car like a Honda Civic, the labour component of the AC compressor cost at an independent shop would range between £140 and £210. An aftermarket complete compressor would range between £110 and £200.
For the same vehicle to be repaired at the dealership, you would have two different repair options. To replace the clutch and coil (usually replaced together), the labour cost would range from around £175 to £250, and the dealership parts around £260 to £400. To replace the entire compressor at the dealer, expect to pay between £650 and £800.
The cost of replacing an AC compressor on a Chevy Silverado at an independent shop would include the labour cost that ranges from £140 to £210, and an entire compressor would range between £260 and £320.
At the dealership, the clutch and coil could be replaced for £320 to £400, and the entire compressor could be replaced for £560 to £640.
At most dealerships, replacing the entire compressor will come with a three-year, 36K mile warranty, whereas most independent shops will have a one-year, 12K mile warranty.
A newer trend is that some aftermarket compressors will have no warranty unless the entire AC system is replaced.
What Are the Components of the Compressor?
The compressor is the most costly component in the AC system and also the most critical to a functioning system. The compressor is composed of three different components, which are as follows:
- The Clutch
The clutch is located on the front of the compressor, and its purpose is to allow the compressor to be engaged or disengaged. The clutch is a friction disc and the pulley for the compressor.
The pulley is turned by the drive belt just like an alternator or power steering pump, for example. But unlike the power steering pump, the compressor cannot be on at all times, so that’s why the clutch exists.
The clutch, when activated, locks itself to the drive belt pulley, causing the compressor to operate.
- The Coil
The coil is an electromagnet. When power is supplied, it becomes magnetic. When the AC is turned on in your vehicle, the coil becomes energised, which causes the clutch to engage due to the magnetic forces.
Once the clutch has become engaged by the coil, the compressor now turns on the drive belt.
- The Compressor
The compressor, when engaged by the clutch and coil, then compresses and pushes refrigerant throughout the AC system. In the olden days, the compressor had serviceable components inside. However, in today’s modern vehicles, the only serviceable components are the clutch, coil, and compressor.
Why Would You Need To Replace It?
There are a couple of reasons why you might need your AC compressor replaced. The most likely reason is usually due to the coil failing, which is the most common cause that independent shops service as most do not service just the coil.
When a coil fails, your AC will not function at all. Without the ability to engage the clutch, with a failed coil, the compressor will never turn on and will not even attempt to cool down the air.
Clutch failure is not as common as coil failure. Sometimes, the clutch will wear out just from age of use as it is a wearable component. When the gap between the two clutch surfaces becomes large, the coil is unable to pull them together to lock up and engage the compressor.
It is very common at the dealership to replace both the clutch and the coil together whenever one of the two components fails.
The compressor is only replaced if it fails when being serviced at the dealership, and it can fail for a couple of reasons. It could be replaced if it’s leaking and there are no serviceable seals.
The compressor could also be replaced if it fails internally and is no longer able to compress the refrigerant gas. Without proper compression, your AC will function very poorly, or not at all.
The only other common failure that would require the compressor to be replaced is if it becomes seized. This happens when there is poor lubrication and can cause the compressor to lock up and not turn at all.
What To Expect
It’s no fun when it’s the middle of the summer and your AC stops working. There are advantages and disadvantages to where you choose to have your repairs performed.
Independent facilities can save you money upfront by replacing the entire compressor assembly for less than what the dealership can replace just a clutch or coil for. However, the lack of a warranty or a short coverage amount can make this less appealing when compared to the dealership warranty.
Dealerships are able to replace only what is actually needed, be it the clutch, coil, or just the compressor. The cost is much greater than the aftermarket parts, but the quality is always much greater.
The dealership will also not require you to replace the entire AC system to have the warranty on your compressor, unlike what some independent places will do.
Replacing your compressor will take several hours for most vehicles. This will call for two to three hours of drive time for standard vehicles, not including the time needed for the evacuation and recharge, which usually takes around an hour.