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In most cases, if your car air conditioner is blowing warm air, A/C Pro is the fast, easy way to fix it yourself and save money.

However, there are situations in which you’ll probably need to take your car to a professional mechanic instead. A/C Pro won’t fix a broken compressor clutch, for instance, or replace a bad condenser coil.

In this article, find out:

  • What scenarios you shouldn’t use A/C pro in
  • When to call a mechanic
  • When to use a different product

While you can often troubleshoot your car’s A/C on your own, save yourself time and money and read on as we cover a list of scenarios in which you should not be using A/C Pro.

Don’t use A/C Pro if:

Your car was built before 1994 and has never been converted from R-12 to R-134a.

This one’s going to be rare because if the A/C has broken down at any point in the past 20 years, it would have likely been converted to R-134a in the process of getting it fixed. However, if you do have an old R-12 system, you can’t use A/C Pro until it’s been converted to R-134a. All cars built since 1994 will have R-134a or R-1234yf systems, which is what A/C Pro is designed for.

You drive a hybrid or electric car.

Don’t ruin your hybrid or electric car with A/C Pro. Most hybrid cars (and all electric vehicles) use an electric A/C compressor, which requires a different type of compressor oil. A/C Pro contains compressor oil, but it’s the type used in regular belt-driven A/C systems.

It took less than two weeks for your A/C to go from cold to hot.

A/C Pro seals small leaks in rubber A/C components, such as O-rings, gaskets, and hoses, which are what usually cause a system to become low on refrigerant. A leak is considered “small” if it takes at least two weeks for the refrigerant to leak out. If your A/C was cold yesterday and today it’s blowing hot air, you have a problem bigger than DIY troubleshooting and A/C Pro can fix.

Before adding A/C Pro, one of the first steps is to use the A/C Pro gauge (which can be bought separately) to check the system pressure. The gauge measures the low-pressure (or suction) side of the A/C system. When the compressor is running, it should create suction and lower the pressure reading. Note that when the compressor is not running, it’s normal for the gauge to show a high reading.

If the pressure is too low due to a lack of refrigerant, adding A/C Pro will bring it up to the correct range. However, if the compressor is running and the pressure is too high, that either means that the system has too much refrigerant or that there is a problem with the compressor. Keep in mind that the belt will be constantly moving, even when the compressor is cycled off. To be sure the compressor is running, watch the center pulley.

The problem persists after you’ve already added A/C Pro.

If you’ve already successfully recharged your A/C system with A/C Pro but experience warm air again after a few weeks or months, this indicates that you have a slow leak in a metal A/C component.

A/C Pro will have sealed any small leaks in the rubber components – which are more common – leaving the issue to be something more complicated. Before adding any more refrigerant, you’ll need to seal the metal leak. You can do this using Super Seal.


If one of those five conditions apply, A/C Pro is currently not for you. However, if your car’s air conditioner is blowing hot air because it’s low on R-134a or R-1234yf refrigerant, and it’s taken at least two weeks to get that way, A/C Pro can fix your problem and save you time and money.

If you have any questions, please contact us.