How To Flush Your Car AC System (Full DIY Cleaning Guide) (2024)

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, as well as how to clean the vents properly.

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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.

  • Manifold gauges
  • AC recovery machine
  • Air compressor
  • Refrigerant
  • Fine brush
  • Car vacuum
  • Cleaner of your choice
  • Steam cleaner
  • New cabin air filter

How To Flush Your Car AC System (Full DIY Cleaning Guide) (1)

Steps To Flush Car AC

  1. Use a fine brush made with microfiber to dust each air vent individually. You don’t need to remove car AC vents just yet.
  2. While brushing, dust is going to break loose. Hold a car vacuum close to your work to suck out the dust as it is removed.
  3. You will want to spray a clean air car vent cleaner onto the dusted area to completely clean it. You can also use a steam cleaner for deeper disinfection. Just make sure the vents are dry when you are finished, or you encourage the growth of mold.
  4. Change the cabin air filter because it can become blocked and dirty causing further musty smells. If filter is new, cleaning the car or RV AC filter also helps.
  5. From outside of the car, you want to spray compressed air into the intake vents. Do this while you have the ventilation running in the vehicle, so all of the air can escape.
  6. 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.
  7. Remove the refrigerant hose from both sides of the condenser (low and high).
  8. Start cleaning the car AC condenser by shooting 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.
  9. 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.
  10. 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.
  11. 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.
  12. With the air conditioner running for about ten minutes, you can also check for leaks with a dye that’s injected into the system.
  13. 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.

The automotive ventilation system consists of the air conditioning and heating units all in one. Air gets pulled into the large duct located at the front of the vehicle while the car is moving. When the air enters, it gets heated or cooled, depending on the fan setting you have chosen.

Heating vs. cooling isn’t much different. When the heat setting is chosen, the air moves through the water-heated radiator while the fans push the air into the car. However, for cooling to occur, the refrigerant must be present in the AC system. This refrigerant gas gets compressed and converted to a liquid that moves through the condenser to remove heat. This process creates the cold air that gets pumped into the cabin.

What Exactly Is a Car Air Conditioner ‘Flush’?

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.

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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.

Related ArticleHow Does Car Air Conditioning Work.

Why Do You Need To Clean Your Car Vents?

Is there a benefit to having clean car AC vents? After all, it doesn’t make sense to learn how to clean out the car air vents if there is no benefit. In reality, there are a lot of reasons to consider cleaning AC vents in a car. For starters, you remove allergens and dust from the system. It can also help reduce the growth of bacteria and mildew.

You also want to know how to clean smelly air vents in a car if odors are present. In general, a car AC vent cleaning can dramatically improve the health and well-being of those inside the cabin while also prolonging the life of the air conditioning parts.

Related ArticleHow to Clean RC AC Filter

How To Tell That Your Car Vents Needs To Be Cleaned

Unpleasant Or Musty Smells Inside The Car

It’s important to clean out the air vents if you begin to smell anything undesirable or musty, similar to dirty gym socks in the car. These smells could indicate the beginning of mold or bacteria growth, which is why you want to take action immediately.

Related ArticleHow to Get Rid of Mold in Car AC

Visible Debris In The Car Vents

You probably aren’t easy on your vehicle, putting it through a lot of stress on a regular basis. Because of all that you use your vehicle for, debris can build up in the car vents, leading you to search out the best way to clean air vents in a car.

Dust, Pollution Or Pollen In Your Area

Even if you aren’t hard on the interior of your vehicle, it’s only natural for pollen, pollution, and other dust to start building up on the vents. Occasionally, you want to clean out the air vents in a car just to remove this build-up and prevent respiratory ailments.

How To Flush Your Car AC System (Full DIY Cleaning Guide) (3)

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.

What happens if you don’t clean your car vents?

Dust and debris will continue building up on the vents. This contamination could lead to the growth of bacteria or mold. Plus, it can reduce the amount of air coming out of the system.

How often should car AC vents be cleaned?

In normal conditions, you want to clean the vents every month or every other. However, if you are spending a lot of time in the vehicle or driving in dusty conditions, you may want to clean them more frequently.

Can you steam clean car vents?

You can use your steam cleaner on the car vents. The biggest trick to remember is that the vents must be completely dried when you are finished. Otherwise, your cleaning only encourages the growth of mold.

How do you remove car vents?

You shouldn’t need to remove the car vents to clean them. However, if removal is required, it’s important to read the directions in the service manual, ensuring that nothing gets broken in the process.

Conclusion

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.

Last Updated on June 2, 2022

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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.

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How To Flush Your Car AC System (Full DIY Cleaning Guide) (2024)

FAQs

What can I use to flush my AC system? ›

AC System Flush- AutoZone Car Care - YouTube

How do you flush a car evaporator? ›

Part 1 Flushing the evaporator in your automotive car truck suv jeep van ...

How do you use a auto AC flush kit? ›

OEMTOOLS 37377 Automotive AC Flush Kit - YouTube

Can you flush a car AC condenser? ›

If an A/C system is contaminated and contains debris, Chrysler says replace the condenser and hoses. If you do flush parts, flush only the condenser, evaporator and hoses. Do not flush a compressor, accumulator, orifice tube or expansion valve. Replace the accumulator, orifice tube or expansion valve.

How do you flush a car AC system at home? ›

How To Flush Auto A/C Systems - YouTube

Can you use brake cleaner to flush AC system? ›

It should work ok. I usually use brake cleaner with no problems. Just blow a lot of air through it to make sure it is all evaperated out.

Can alcohol be used to flush AC system? ›

Alcohol is especially great for final flushing. You can also opt for mineral spirits, particularly if you're searching for an economical flushing solvent or even ac flush solvent alternatives like brake cleaners for quality flushing.

What is in AC flush solvent? ›

An airconditioning system flush solvent is prepared by mixing 60-70% heptane with 29-40% isopropyl alcohol and up to 1% fragrance. Preferably, the mixture comprises 69.5% heptane, 29.5% isopropyl alcohol and 1% fragrance.

Can you use mineral spirits to flush AC system? ›

FLUSHING WITH MINERAL SPIRITS

Using mineral spirits may void the component Warranty. Mineral spirits are flammable. Mineral sprits are slow to evaporate so some may be left in the system. Residual flush solvent can contaminate and damage an air conditioning system!

How much AC flush do I need? ›

You should not need more than 1 quart of flush. The brand does not matter. They are all made from the same chemicals.

How do you flush an AC evaporator core? ›

Examine the AC evaporator core and determine whether it only needs cleaning. Apply an evap core cleaner and let it sit for 30 minutes. Rinse the treated AC evaporator core with water and a cloth or rag. Remove all the excess moisture and dry the evaporator core with a fan.

How do you clean an evaporator coil without removing the dashboard? ›

  1. Step 1: Remove the Glove Box.
  2. Step 2: Access the Evaporator Coil.
  3. Step 3: Spray the Cleaner on the Evaporator Coil Through the Access Point.
  4. Step 4: Rinse the Evaporator Coil.
  5. Step 5: Dry the Evaporator Coil.
  6. Step 6: Put Back the Blower Fan or Resistor Block or Seal the Hole You Drilled.
  7. Step 7: Put Back the Glove Box.
Jun 2, 2022

Can you flush a serpentine flow condenser? ›

The parallel flow condenser is by far the most efficient condenser to use with R134a refrigerant. The multi-channel construction and multiple passes the refrigerant makes through the condenser allows maximum heat transfer.

How do you unclog a condenser coil? ›

How To Clean Your AC Condenser Coil - YouTube

How much does it cost to flush your car AC? ›

The Average Cost to Recharge Your Car Air Conditioner Is $20 to $155, Depending on if You Go to the Mechanic or DIY. This price range is based on national averages for all vehicles and does not factor in taxes, fees, or your particular make and model.

What is AC flush solvent? ›

An airconditioning system flush solvent is prepared by mixing 60-70% heptane with 29-40% isopropyl alcohol and up to 1% fragrance. Preferably, the mixture comprises 69.5% heptane, 29.5% isopropyl alcohol and 1% fragrance.

How do you flush an AC with bleach? ›

You can use a cloth or stiff brush. Then, remove the plug or cap from the access point (the T-shaped vent) and slowly pour either 1 cup of distilled vinegar or 1 cup of bleach solution into the drain line. Wait for 10 minutes to 1 hour for the blockage to be dissolved, depending on the severity of the clog.

Can you use denatured alcohol to flush AC system? ›

Choosing the ideal flushing liquid

In this article, we have chosen denatured alcohol as our flushing liquid because it virtually leaves no residue that can hurt oil viscosity, potentially causing compressor breakdown. Alcohol is especially great for final flushing.

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