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How To Replace AC Compressor In a Car


Your car’s air conditioning system shields you from scorching heat, ensuring a pleasant driving experience. Even in hot weather, your AC keeps you and your cabin cool, comfortable & relaxed. However, if your AC starts to blow hot air instead of the cold one, it’s time to replace your AC compressor. 

The air conditioning compressor, or AC compressor is responsible for cooling the air. Together with refrigerant gas, the condenser & the evaporator, it forms an integral part of the cooling system. 


The cooling process is quite simple: 

  1. The A/C compressor works by compressing the refrigerant gas, increasing its temperature and pressure. 
  2. The hot pressured gas then passes through the condenser, turning into cool, low-pressure liquid.
  3. Then the liquid is directed towards the cold evaporator by a fan.
  4. The heat is absorbed and exits the cabin, ultimately cooling the air, giving the driver respite from the heat and comfort of the cool air.  

With time and certain other factors, the ac compressor may lose its efficiency. May start making noises, blow hot air, overheat or fail to perform the required task. If you repeatedly encounter such issues, it would be best to replace your ac compressor with a new one. 

In this guide, we’ll walk you through the step-by-step process of replacing your car’s ac compressor. 

Safety First

Before you begin, you need to follow these safety precautions:

Turn Off the Power: You need to be careful while handling air conditioning systems, as they are extremely dangerous. To avoid electrical shocks, first disconnect the power.

Wear Safety Gear: Protect yourself by wearing some good quality safety glasses and gloves. Avoid touching any wires or sharp components.

Follow the Law: In many jurisdictions, only certified professionals with a license can deal or handle refrigerants. So it would be best to seek professional help, if you fall under such jurisdictions.

Gather your tools and materials

To replace your AC compressor, you’ll need the following tools and materials:

  1. Wrenches and sockets 
  2. Screwdrivers 
  3. Pliers 
  4. A/C manifold gauge set 
  5. Refrigerant recovery machine 
  6. Vacuum pump 
  7. Safety glasses and gloves

Step 1: Locate and Access the AC Compressor

The first step is to locate the ac compressor. Open the hood and scan the engine compartment. Carefully check all sides of the engine. The ac compressor is generally fitted at the front of the engine. 


  1. Disconnect the battery before proceeding. 
  2. Recover the refrigerant 
  3. Only professionals can recover the refrigerant using a refrigerant       machine. 
  4. Check for any specific instructions before installing the new ac compressor

Step 2: Remove the Old Compressor

Don’t remove the old compressor unless the refrigerant is safely recovered. The old compressor is perfectly placed in the mounting bracket. You’ll need a socket and wrench here to carefully unbolt the old compressor from its mounting bracket. Once you unbolt it, cautiously lift the old ac compressor out of its mounting bracket. 


  1. Ac compressor is a heavy object. 
  2. Cautiously lift it with both hands. 
  3. Wear safety gloves. 
  4. Disconnect the refrigerant lines and electrical connections. 

Step 3: Replace the O-rings

Replacing the O-rings is a simple three step process. Locate the O-rings, remove them and install the new ones. O-rings maintain a proper seal in your AC system. If you found any leakage, then it means the seal is loose and you need to repair or replace the O-rings. You’ll need a screwdriver to remove the O-rings. The new O-rings must be lubricated before being replaced.

Step 4: Install the New Compressor

It’s now time to install the new ac compressor. Just check the mounting bracket once again. Clean it to remove any dust particles or contaminants. Now place the new acc compressor perfectly in the mounting bracket. The new acc compressor must be placed exactly as the older version was placed: Perfectly aligned, oriented and correct. 

Secure the new ac compressor, by doing the following 

  1. Rejoin the bolts 
  2. Join the refrigerant lines 
  3. Plug the electrical connecter 
  4. Rejoin the compressor belt 

Check for any issues after Installation

It’s important to note that even after replacing the ac compressor, you’ll encounter some issues. So it’s good to have some troubleshooting tips that’ll make your job a little easy. Replacing your car’s ac compressor doesn’t always guarantee a flawless air conditioning system. Potential issues may include leaks, inadequate cooling or no cooling at all, electrical issues or strange noises or any other complications that may spoil your driving experience. Check the power, connections & all the wires. Tighten the seals and ensure there are no leaks. 

However, your air conditioning system may encounter issues due to the following reasons. 

  1. Leakages 
  2. Incomplete vacuuming 
  3. Inadequate recharging 
  4. Electrical or power problem 
  5. Loose seals & bolts 
  6. Compressor clutch not working 


If you are unable to spot any issues, then it’s time for you to seek professional help. Go to a certified professional and get your air conditioning system properly vacuumed and recharged. And remember, In many jurisdictions, only certified professionals with a license can deal or handle refrigerants. 

Evacuating & Recharging The Refrigerant

Replacing your car’s ac compressor is not an easy job. It’s definitely challenging when you have little knowledge and try to do it yourself. But follow these steps accurately and get the job done. But before replacing your car’s ac compressor, it should be properly vacuumed. And only a certified professional can vacuum the air conditioning system. Vacuuming your ac system yourself is against the law, as refrigerants fall under strict regulations.

Caution: Only a certified professional can vacuum and recharge your ac.
In many jurisdictions, only certified professionals with a license can deal or handle refrigerants. So it would be best to seek professional help, if you fall under such jurisdictions.


While driving a car, comfort comes first. And nothing gives better comfort than a proper working air conditioning system. The cool air blowing from the AC shields you from the heat & keeps you in a good mood as well. However, there are certain factors that contribute to your ac not working properly: ac compressor is one of them. Ac compressor is responsible for cooling the air. But if your AC is blowing hot air instead of cold air, then you need to replace the ac compressor.

Ac compressor is a crucial part of the air conditioning system and it needs to work properly if you want to stay away from the scorching heat that will spoil your driving experience.

So follow the easy steps and replace your car’s ac compressor. Get a profession to properly vacuum and recharge your ac before you install the new one.