How to flush AC system with alcohol

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Are you wondering why your AC does not seem to work as well as it used to the first day you bought it? Well, maybe there is a lot of debris trapped inside that is messing its performance.

The good news is that most of AC failures can be cured by simply flushing your system and removing that nasty dirt, even without calling your technician.

In this article, we show you how to flush AC system with alcohol effectively and get your air conditioner up and cooling again.

Let’s get started.

How to flush AC system with alcohol

Flushing your AC is arguably the best thing you can do to your AC to get it back into top shape, without spending too much time or money.

And unless your AC has some underlying mechanical problems, this should promptly restore your car’s usual cooling performance.


Why flush?

Flushing is an easy way to remove impurities and those annoying particles from the air-conditioning circuit, preventing the need for more expensive repairs down the road.

It also prevents damage to essential parts of your AC system such as the compressor and the condenser.

Of course, flushing your air conditioner is necessary every time you change the compressor (if it has come to that).


Choosing the ideal flushing liquid

Flushing your AC system should be fun especially if you do it carefully and correctly using an ideal flushing liquid that evaporates at room temperature without leaving any residue.

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.

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.


How to flush AC system with alcohol- step by step

Although flushing an AC may not be a five-finger exercise, the following procedure will make your cleaning work on your air conditioning system less of a hassle.


  • Wear protection

Never start your job without the appropriate eye protection since the flushing liquid can splash into your eyes and cause irritation and or long-term eye damage.

On top of this, remember to wear tough rubber gloves to protect your hands from irritation and other potential injuries (remember some sharp metal parts make up your AC).

  • Assemble the right tools for the job

At the same time, gather the appropriate tools for the job including the right refrigerant recovery device, lubricants, adjustable wrench, and an air compressor.

How to flush AC system with alcohol- the flushing procedure

Keep in mind that you should never flush the expansion valve, the accumulator, and the orifice tube because you risk damaging them.

You should also avoid flushing the compressor because it is unlikely to survive this.

Let’s now get our hands dirty!

Step 1: Empty the refrigerant                                                                                                  

First, empty the ac system refrigerant by following the guidelines issued by the authorities.

Step 2: Disconnect stuff                                                                                                             

Secondly, disconnect all pipes from components that you want to flush, starting with the orifice tube. For starters, the orifice tube is located in the liquid line or at the evaporator.

Also take out hoses that may get into your way, the evaporator, condenser, etc.

Step 3: Flush the condenser                                                                                                    

Locate the high-side inlet on the condenser, pour alcohol into the unit via this hole, and start applying compressed air in there.

You don’t want alcohol to spill all over the place so get a way of catching it as it oozes out of the condenser’s outlet port.

A rag, a clean cloth, or anything similar can suffice for this.

Another good way of capturing the dirty alcohol would be via a hose connected to the exit end of the unit and directed into a collecting container.

Now, continue to pressurize the condenser until there are no more traces of contaminants in the solvent.

Step 5: Flush the evaporator                                                                                                   

Now, flush the evaporator by repeating the steps you’ve used to flush the condenser (pouring alcohol and applying compressed air until all the debris is forced out).

Expert tip:

When flushing, you should first consider backflushing. This simply means flushing from the inlet to the outlet on evaporators and condensers to force out debris.

Thereafter, flush the units repeatedly from the outlet to inlet to ensure you have dislodged all filth.

Step 6: Recharge the evaporator                                                                                           

After all the dirt has been flushed out, reassemble everything, return the refrigerant, and finally test your AC for proper cooling performance.

How to flush AC system with alcohol: Useful tips

· Replace parts that need replacing

Most manufacturers recommend the replacement of components such as the drier within a set time frame.

Take advantage of the flushing process and change these parts (it’s also important that you replace the accumulator and the orifice tube, if necessary) before you recharge the system.

· Add the correct amount of lubricant

Needless to say, it’s important to add back the ounces of oil that had been removed from the various parts in the AC system when carrying out this vital maintenance task.

· Allow the parts time to dry

After you’re done with the cleaning, leave the various components out in the open so that they can dry properly.

· Check and repair any leaks

Investigate the ducts for leaks before you restore the components to their locations and patch any you have spotted up with duct tape.


Final thoughts

We believe that you now know how to flush AC with alcohol within a few minutes if you’re a fan of DIY projects.

Feel free to call in a professional mechanic if you have any doubts about some of the steps or if it looks like it might be too much work.

One more thing: Don’t forget the immense flammability hazard that alcohol is.

As such, you should avoid risky practices such as smoking while flushing the AC system with alcohol.

PS: It is important you understand that a parallel flow condenser_cannot_be easily flushed. You see, flushing will_not_always_clean a parallel flow condenser, and only serpentine flow condensers can be  properly flushed clean.

I’m saying so because most automotive condensers these days are parallel flow – and that means you often have to replace them since they won’t always flush clean.


Too much oil in AC system symptoms and troubleshooting tips


1 thought on “How to flush AC system with alcohol”

  1. If your AC system needs to be flushed with alcohol, keep a few things in mind. First, make sure that the flushing fluid is of the correct concentration. Second, choose a liquid flushing agent that is non-toxic and easy to use. And finally, be sure to follow all safety precautions when flushing your AC system with alcohol.

    When choosing the right flushing fluid for an AC system, it’s important to consider both concentration and toxicity. Most commercial flushing agents are designed at a specific concentration (often 50% or more), so make sure you get the right product for your needs. In addition, some solvents, like ethanol, are relatively safe and easy to use; others, like butane or propane, can be dangerous if mishandled.


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