6 Signs Of Low Freon In Car

Freon is the coolant that makes your car AC tick. Here are a few signs of low freon in car that you need to watch out for

If you suddenly feel that your car’s air conditioning has stopped working and it is not throwing cold air, then your car’s AC might be running low on freon.

Most air conditioners use freon gas as a refrigerant. The compressor inside the air conditioner is responsible for exerting pressure on the freon gas to convert it into a liquid from a gas.

This change of the freon gas from a gaseous state to a liquid form is what cools the air around it. However, any potential leak in the air conditioner will cause the freon gas to leak, and your AC will not cool anything anymore.

In this article, we will discuss the potential signs that can tell you whether your system is leaking or not.

Signs Of Low Freon In Car

What are Freon and its advantages?

Freon is a unique substance most prominently used in air conditioners as a refrigerant. The freon gas contains halogenated hydrocarbons such as chlorine, fluoride, and carbon inside this gas. These halogen gases cool the air inside the car cabin so that you can drive comfortably, even on a hot day.

CFCs contribute to the depletion of the ozone layer. Initially, when the freon gas was introduced to the market, it was not very well received. 

This was because the freon gas had traces of chlorofluorocarbons. After that, several manufacturers tried to develop a freon gas that did not harm the ozone layer. The newer chemicals used in air conditioners are called hydrofluorocarbons and don’t harm the environment.

Some advantages of freon gas are:-

  • It helps to keep a cooler temperature inside the car.
  • Freon gas has a lower boiling point, which helps to deal with extreme temperatures efficiently.
  • They are not like CFCs and do not harm animals.
  • This gas has a low contribution to the greenhouse effect.


You might also like to read: How Long Can I Drive With Low Coolant?


How To Check Freon In Car?

If you wish to check freon in your car, then you need to simply follow these steps:-

  • Open the front hood of your car, and try to locate the AC compressor as it should be on either side of the engine.
  • Now with the help of the screwdriver open the cover. Then use a wrench to remove the bolts from the compressor and open it.
  • Now you will find two tanks on both the sides of the compressor with a pressure valve on top with marking  0 to 300 psi. If the pressure levels of freon is below 50psi you will have to add a full can of freon or else half will do if level is in between 50 to 150 psi. If it is above 150 psi you don’t need to add freon.

Symptoms of Low Freon or Refrigerant Leak In Car

There can be few obvious signs of low freon in your car, and you can easily observe these signs and try to resolve the issue.

Air Conditioning units not cooling

When the AC in your car starts giving out warm air instead of cool air, it is the first symptom of low freon levels or no freon in the system.

Coolant leaking

If you see a thin greasy fluid in your car system or if you see this fluid leaking underneath your car. You’ll need a freon refill for your AC as a coolant leak will not allow the AC to cool anything.

Signs Of Low Freon In Car

Low gauge readings

You can check the freon level in your car by checking the pressure readings from the AC. When your AC has freon, it should have higher pressure ratings close to 250 or 300 psi. These ratings can drop to 25 or 30 psi on the lower side. AC ratings lower than this means that the freon level is shallow.

Sight glass

The sight glass can also identify freon levels in your car. With this glass, you will be able to see the movement of the freon inside the system. If you cannot see freon moving with this glass, then your AC has a low quantity of it.


You might also like to read: Why Do I Get A Noisy Power Steering Pump When Cold?


Clutch failure

This is a prevalent indicator of low freon inside the car. If there is sufficient freon in the car, you should hear a clicking sound whenever you switch on the AC. As the freon levels drop, this clicking sound will disappear. Once you cannot hear any clicking sound, then it means that the freon is too low inside the AC.

Ice on the compressor

When your AC compressor starts freezing instead of cooling, it is a sign of low freon inside the system. The reason why the compressor starts freezing is that the moisture takes the place of freon.

How Much Does Freon Cost?

The freon cost varies depending on the type of freon you want for your AC. Then there are other factors, such as the locality in which you are purchasing the gas and the quantity you are purchasing. A gallon of freon gas can cost around $25 to $30. Buying freon in bulk will be a bit cheaper than this.

How To Add Freon To Car AC

You must recharge your car with freon gas after your car AC service. Once you know that your AC’s compressor does not have any freon gas left, then you either fill this gas yourself or contact professional technicians. You will need a bit of experience to do it correctly.

If you want to refill the gas on your own, you must find the circuit inlet first. There will be two hoses, one pipe is for high pressure, and the other is for lower pressure.

The higher pressure pipe is the one that is thinner between the two tubes and is connected to the high-side service port. The other wider pipe is the low-pressure pipe. Once you know the location of the circuit inlet, you need to unscrew the plugs from them.

Suppose you cannot determine which pipe is which, then it is ideal that you refer to the instruction manual. In the next step, you must connect the machine to these pipes. The pressure gauge reading should be somewhere between eight and ten. Make sure that all the other valves and vents on the circuit are tightly closed.

Once the entire circuit is closed, you must continue with gas recharge. After refilling the freon in the course, your AC should start cooling again.

Signs Of Low Freon In Car

Frequently Asked Questions

What happens when your car is low on Freon? 

If your car is low on freon, then the AC in your vehicle will stop cooling. You will only get air at average or room temperature blowing out of the AC. If the freon level gets very low, the clutch can start acting up. It may fail to engage correctly. This is a sign that your AC compressor has nothing left to pressurize.

How often does Freon gas need to be replaced in the car? 

Generally, AC lasts about five years, although they require regular maintenance and cleaning up to perform as efficiently as possible. You will not be required to fill freon in your AC since this gas is regulated in a closed system inside the AC. Unless there is a leak inside your AC, you will need to replace this gas and get it filled again.

Can I run AC with a low Freon? 

Yes, you can run your AC with a low amount of freon for some time. But you should not continue to run your AC like this as it will not work efficiently. Most parts inside an AC have a minimum set quantity for the chemical blend; otherwise, they cannot work correctly.

Wrap Up

Freon is an essential gas and part of the air conditioning system. Without this gas, your AC will stop cooling the air. You can refill the freon gas on your own, or you can take your vehicle to a mechanic that will refill the freon gas for you. Identifying the signs that your AC has stopped working can be pretty obvious. Thank you for reading the article, we hope that we have answered all your questions about your car AC’s freon coolant.

Photo of author

Sean Mendez

Hi, I am Sean, a self-confessed petrolhead. I live in Boise, Idaho with a busy family of four and our energetic Labrador retriever. Thank you for visiting my website. You can find my email on the contact page.

Leave a Comment