Informational Guide

How To Flush Your Car AC System

Keeping your car’s AC working requires regular maintenance. Learning how to clean the car air conditioner is vital for a comfortable ride.

by Josh M

To keep the HVAC system in your car working right, you need to perform regular maintenance. Learning how to clean the car air conditioner is a vital way to ensure the cabin is comfortable, especially when it gets hot.

In this article, we cover how to clean a car AC system and show you the way to perform a DIY car AC flush.

Car Interior Air Conditioning

Before you learn how to flush the car AC system, you want to know what this preventative service is. Technicians flush the car AC system to clean out any sediment and sludge from the drains and hoses. During the car AC flush, technicians also check the system for leaks.

Why Is Flushing The AC Necessary for Car Owners?

The typical car air conditioning cleaning ensures that the system is free of any contamination that would otherwise block efficiency. Anything that can block the valves, hoses, and lines can harm the air conditioning operation.

Blockages in the system can also keep the compressor from working correctly. If the flow of refrigerant or oil is blocked, the system fails to work as it should. The compressor requires oil for lubrication, just like the car motor. Without it, vital parts are going to wear out from the friction.

You can tell when it’s time to learn how to clean the aircon in a car. The air being pumped out will start appearing warmer, and the flow itself might be reduced.

How To Flush Your Car AC: DIY Cleaning Guide

What You’ll Need

To learn how to flush car AC lines, you will need some sophisticated equipment. For this reason, many people choose not to learn how to flush your car AC system and take it to a local shop instead. If you choose to clean out the car AC system yourself, these are the parts you need.

Car Interior AC Controls

Steps To Flush Car AC

  1. Connect the manifold gauges to the fittings. With the recovery machine, you want to completely evacuate the system. You can’t move on until the pressure is reading 0 psi.
  2. Remove the refrigerant hose from both sides of the condenser (low and high).
  3. Shoot compressed air into the high side, thereby forcing debris from the outlet hole in the condenser. Keep doing this until all contaminants get removed from the air conditioning. If the condenser contains an internal tubing, there’s no way to flush it. Instead, you would need to replace it.
  4. You are now ready to learn how to clean an AC accumulator. Remove the mounting brackets securing the accumulator, plus the expansion valve or orifice tube. Inspect these parts for any signs of damage. Replace them if needed.
  5. If you want to learn how to clean the car AC compressor, you can drain it and refill it with refrigerant oil. You can also clean out the car AC evaporator, but this could be difficult to reach.
  6. Once the system is free from debris, you can reassemble everything. It’s also time to put refrigerant back into the system. Recharge it to the appropriate specifications and ensure the proper pressure is set.
  7. With the air conditioner running for about ten minutes, you can also check for leaks with a dye that’s injected into the system.
  8. Finally, you can learn how to clean the car AC vent, especially if there is a moldy or musty smell. The car vents require regular cleaning to ensure the air you are breathing is safe. With special sprays, you can disinfect the car AC. You can also use a vacuum cleaner to remove any debris or dust stuck in the vents.

If any of these tasks seem too complicated for you, it’s best to visit a qualified shop to have the flush performed. If you damage one part in the process, you could be looking at an extensive repair bill, making the at-home maintenance task not worth much.

Car AC Controls with LED

People Also Ask (FAQ)

Is cleaning and flushing an AC the same thing?

The terms cleaning the AC or flushing the air conditioning can be used interchangeably. Both services ensure that the air conditioning system is free of debris that could lead to a blockage.

How often should you flush your car’s AC?

You want to schedule AC service on the vehicle once a year, particularly before it gets hot. As the technician checks the system, they will know whether it needs to be flushed or not.

How much does it cost to flush the car’s AC via a mechanic?

The typical car AC flush and recharge cost will be around $200. However, depending on the vehicle size and what needs to happen, you could spend slightly less or more.

How long does it take to flush the car’s AC?

It could take an hour or longer to flush the system. The most time-consuming aspect can be evacuating the system. If you don’t have the right equipment, it could take you longer to perform the task versus having a professional handle it.


If you have the skills and equipment, you can perform your own AC flush on a car. It’s possible to save a little bit of money by performing this air conditioning service on your own.

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.