Steps On How To Check Freon Level In Car

In most cases, when your AC stops working, all you may have to do is check the freon level and recharge it. There may be times when other serious problems are affecting your AC system but checking the freon level is worth a try. This article discusses how to check freon level in car along with other relevant subtopics for better understanding, so read on!

What Are The Signs Of Low Freon?

Before discussing how to check freon level in car, you have to know about the certain signs that your car shows when its freon level is low. should be easy to tell when your AC stops working, especially in hotter climates, but here are some simple ways to start your diagnosis. Here are a few signs that indicate low freon

1. The AC Is Not Blowing Cold Air But Is Just Air

This is one important sign that indicates that all of your AC’s freon has leaked from your car. This may either happen suddenly or over a period of time. However, all you need to do in such a situation is to add freon to your AC.

2. The AC Is Not As Cold As It Used To Be

You may notice that your car’s AC does not get as cold as it used to. There may still be cold air coming from vents but not as cold as it used to be. This may be an indication that your car’s freon is leaking.

3. You Can’t Hear The AC Clutch When You Turn On The AC

You may be familiar with the usual clicking noise when you turn the AC on. If you are not hearing that sound anymore, it may be an indication of no freon in your unit. The clutch won’t engage when there is no freon in your unit. Thus adding freon will help to engage the AC clutch again.

4. Visible Leakage Of Freon

If you are seeing visible leakage on your AC lines or in the interior of the car, it may be a visible indication of freon leakage. This will cause the freon level in your AC system very low.

5. There Is Visible Ice On the AC Compressor

When your AC compressor is drained of freon, all that would be left is water. Without freon, the water will freeze, and you will notice frozen water in and around your compressor.

How To Check Freon Level In Car?

Now to the main topic, how to check freon level in car. Here are the materials required and all the steps that are involved in the process!

1. Tools Needed

There are a few materials that you will need to complete the process well. Make sure to have all the below tools before going into the steps involved.

a. Protective Mechanic Gloves

Make sure to wear protective mechanical gloves as you will have to work with chemicals such as freon like R-134A refrigerant.

b. Protective Safety Glasses

Protective Safety Glasses are a must in this process. Make sure to wear a good quality to avoid any sort of issue that may happen during the process.

c. R-134A refrigerant + Recharge Hose And Guage Kit

These items are available in the market as combo kits. Good ones will allow you to recharge your AC with ease and the recharger hose and gauge can be reused on any can of R-134A refrigerant for many future uses.

2. Steps To Check The Freon Yourself

The first thing you have to check before diving deeper into the process is to see if your car uses R-134A refrigerant. The easiest way to know this is by knowing your car manufacturer. Most cars that are manufactured after 1994 use R-134A refrigerant as their AC system’s freon. The R-134A refrigerants can be purchased easily and used by anyone.

With that said, here is your step-by-step guide to checking your freon level and recharging your AC by adding more freon.

Step 1: Locate The Low-pressure Service Port After Opening The Hood Of The Car

The AC compressor of your car can only compress gas and not liquids. So it is important that only freon gas enters the AC compressor and not liquid. Some liquid freon may flow out of the accumulator through the evaporator coil into the accumulator where liquid refrigerant and oil are stored.

The low-pressure service port is located between the compressor and the evaporator. An easy way to find it is to locate the larger of the two AC lines. The low-pressure service port on the larger line also has a smaller valve than the high-pressure port which is found on the smaller of the two lines. You may be able to notice an ‘L’ on the cap on the valve of the low-pressure service port.

Step 2: Turn On Your Car And The AC

Now turn your car key and start it. Turn air setting to maximum on your fans and then switch on the AC. If your car is equipped with a ‘Max-AC feature, switch that on as well. If you have a “recirculation” feature, turn this on as well.

Step 3: Run A Low-pressure Service Port AC Diagnostic

Attach the coupler from your recharge kit to the low-pressure service port while your car is still running. Simply remove the cap from the port and push the coupler onto the port. Make sure the can of freon is disconnected when testing your freon level.

At this point, the pressure will be engaged and you can take your reading. Use the gauge that is attached to the hose to find out how much freon is in your AC unit.

If the gauge is showing the refrigerant level in the red zone, it means that there is too much freon in your AC system. This would require an entirely different service that would require the help of a licensed technician.


Follow all the above-mentioned steps for how to check freon level in car carefully. This will help you know whether you are low or more on freon. If you are low on freon, you can set up the freon and proceed to add it to your AC system carefully. This is a simple procedure that you can do with ease. Hope you found this article helpful!

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