3 Steps To Check Freon Level In Car And How To Recharge A/C

If you are worried about why your car’s air conditioning is not blowing cold air, you have to check Freon level in your car.

Frequently checking Freon in car also is a good practice for a car owner because a leak of Freon in your car A/C can make your car overheat. So, better be aware of Freon in your car.

Even if you follow this post, you will know how to check Freon level in the car within only 10 minutes. But the interesting thing is many car owners go to a car mechanic to know the Freon level in their car.

Whether you remove Freon from the car or recharge, first testing the Freon level in car is always recommended.

You will also know how to recharge AC in car. Knowing only how to check Ac pressure in car is not enough because telling if your car AC needs Freon should also be in your mind.

What Is Freon In A Car

Refrigerant is a chemical that is used to provide cool air in your vehicle and that gas called Freon.

Freon is a non-combustible gas. Freon also has no color and is non-flammable. Though Freon is low toxic so, it can harm your screen and eyes.

Freon is mostly used as a refrigerant in air conditioning applications. Whether you have home air conditioning or car air conditioning, both use A/C using Freon to blow cold air. Air conditioning can not blow cool air without Freon.

How Does Freon Work

Freon gas needs to undergo an evaporation process. And the Freon evaporation process is the same for all refrigerators.

In the evaporation process, the air conditioning makes Freon liquid and again makes it gaseous.

When the Freon gets evaporated A/C’s fan brings air from the outside and Freon cold air and eventually produces that air from the air conditioner.

Tools Require To Check Freon Level In Car

Appropriate tools always help you most to check Freon level in car. Here are the tools you will need to test refrigerant level in car.

  • A/C Gauges
  • Thermometer
  • Safety Goggles

You can find these required tools are available in any auto shop to buy, or you can also rent at most large auto parts stores in your area.

To check Freon level in a car, you don’t need to be a professional or auto mechanic. But you should have some experience in a car or if you have a little bit of a home mechanic habit is enough.

How To Check Freon in Car

In order to check Freon in car, you will need air conditioning gauges and a thermometer. Quick inspection around your car air conditioning will help you to check the AC pressure properly in your car.

Steps to check Freon in car:

  1. Attach The Gauges To The Service Ports
  2. Set The Air Conditioner Max A/C
  3. Allow The Compressor
how to check freon level in car
How to check Freon level in car

Step 1: Attach The Gauges To The Service Ports

gauges attach to the service ports
Attach the gauges to Service ports

You have to attach the gauges to the service ports to check Freon in car. Every car has two pressure service ports: the low-pressure service port and the high-pressure service port. A low-pressure service port is also known as a Low-side service port.

The low-pressure or low-side service port will be between the accumulator (located on the car’s passenger side of the firewall) and the compressor.

On the other hand, the high-pressure or High-side service port is located on the line between the condenser (located in front of the radiator) and the evaporator on the firewall.

If you don’t find the low-pressure service port and high-side pressure service port, bring your car’s service manual for more information on the exact location of your vehicle.

Step 2: Set The Air Conditioner Max A/C

set the air conditioner max a/c
Set The Air Conditioner Max A/C

First, start your car’s engine and then set the air conditioning to the highest level or max A/C. Every car has different types of air conditioning controllers.

If your car’s air conditioning system has a recirculation air switch or button, select recirculation air.

Next, put the thermometer into the center air conditioning vent on the dash. You attached the gauges to the service port and placed the thermometer into the center A/C vent in your car.

Now, you need to follow only one more step to check the Freon level in a car.

Step 3: Allow The Compressor

allow the compressor
Allow The Compressor

Allow a few minutes for the compressor to cycle and the pressures to stabilize, and then you get the measurement of Freon.

In a normal system, you have to remember that the low-pressure service port will read anywhere from 25 to 45 psi. Actually, the service port score also depends on the outside temperature.

If the outside temperature is higher, then you get higher gauge reading. And the high-pressure service port side will read between 250 psi and 400 psi. You already know this depends on the outside temperature.

If you read lower than this on both sides, this indicates the low refrigerant level. Read the temperature on the thermometer.

If the temperature is 40 degrees Fahrenheit or lower than outside temperatures, indicate normal system function.

This is how you can check Freon in the car with gauges. While checking Freon in car, you should not hesitate.

And it’s always better to know the right method to check the refrigerant level in car before you do it. If you follow this method of testing Freon level in a car, you should check Freon in car successfully.

Symptoms Of Low Freon In Car

Symptoms of low freon in car
Symptoms Of Low Freon In Car

If your car air conditioner blows warm air or is not cold enough, this is the most common symptom that tells Freon is low in car.

Visible ice on the car air conditioning compressor is another way to tell your car A/C needs Freon.

There are several signs to tell low Freon in the car. A proper inspection around your car air conditioning also will help to know Freon is low.

Air Conditioner Loss Cooling Capability

If you notice that your car’s air conditioner has blown cold air, but now it’s blowing warm air or not cool enough as it should be, this is occurring for low Freon in the car.

This is the most obvious symptom that a vehicle needs to be recharged. The low-level Freon can affect the operation of your vehicle system.

So, you should notice the lack of Freon before it brings a huge problem in a car.

Listen For The A/C Clutch To Engage

By hearing the AC clutch, you can tell low Freon in your car. When you turn your car’s air conditioner on, you should be able to hear the familiar clicking sound of your car air conditioner clutch engaging.

The clutch works by reading Freon levels. When the Freon level drops too low, the pressure will not activate. And the clutch will not engage.

Without the car’s air conditioner clutch engaged, the system will not be able to circulate.

Ice On Compressor

If you see the ice on the compressor could indicate low Freon levels. Ice on compressors usually causes moisture to take the place of Freon.

When your car has no Freon in the car AC line, there is just water left. Without Freon, the water will freeze. And you can see ice on the compressor.

A compressor is the primary component of your air conditioning. So, it should be clean and have proper custody.

A faulty compressor can shake your car when AC is on and also bring some costly issues to your car.

Visible Refrigerant Leaks In The Car

The refrigerant leak from a car is very unusual, but this can be a most serious sign that the car needs an AC recharge.

If you spot any sign of a refrigerant leak in your car, you need to fix that right away; otherwise, the Freon level will never be sufficient in your car.

With these four low Freon signs, you can tell if your car AC needs Freon.

Try to measure the air cooling level that is coming out from your car air conditioner because this is the easiest and most common way to tell if your car AC needs Freon.

How To Recharge AC In Car

Using some of the basics tools and knowing the right method will help you recharge AC in the car. If you notice your car’s air conditioner not blowing cold air, recharge your car AC.

Step 1: Find the Low side port

To recharge AC in car, you have to find the Low side port of your car’s air conditioner. The low side port will be in the barb on the larger tube between the A/C compressor and the evaporator.

Step 2: Attach the can of refrigerant

After you find the low side port of your car air conditioner now you need to screw the dispenser hose and gauge onto the can of refrigerant which you bought recently.

Pulling back the outer slip ring to attach to the low side port. After that, push it on and release the ring.

Step 3: Start the engine

Start the engine and set your car air conditioner at max. After setting the air conditioner on max now, you need to check the gauge reading.

Make sure the compressor clutch has to be engaged, and the front of the compressor is spinning.

If you are reading lower than 20 psi on the gauge, the compressor is not engaged properly.

When you are recharging the air conditioner, shake the refrigerant can first and every 5-6 seconds later but don’t continually shake.

Step 4: Continue dispensing refrigerant

Now, you need to continue dispensing refrigerants to your desired level.

You should follow the refrigerant pressure chart in the refrigerant instructions. Do not over-pressurize your car air conditioning system.

Step 5: Check the air temperature

Using the thermometer, check the air temperature. After finishing the recharging A/C in your car, it’s time to check.

Turn on the A/C, hold the thermometer in front of any AC vents, and measure the air temperature. We should see 28 degrees (fully charged) on the thermometer.

You just finished recharging your car air conditioner. Take your car to a test drive to check the A/C air temperature. Your car air conditioner will blow more cold air than before.

Why Does Your Air Conditioning Need Recharging?

Air conditioners need to be recharged on an annual basis. If your car is not blowing cold air and also you see the refrigerant leak in your car. Then you need to recharge your car’s air conditioner.

But if your car’s A/C system stops working and the fan continues to blow warm air, and you see the leak in the hose, then the connector or the other part of the system is probably the reason for this.

The car’s air conditioner recharging is important not only for cold air but also for your car.

When Your car’s air conditioner begins to lose power and doesn’t blow cool air, this may cause your car’s AC to need a recharge.

If you add Freon or refrigerant in your car, this will start blowing cold air.

Always you have to remember that adding more refrigerant in your car can bring a big issue for your car.

Similarly, if you do not add a sufficient level of Freon in the car, this also brings a problem to your car.

Car A/C system’s issues can take out huge money from your pocket. Issues like car shake when ac is on and so on. That’s why you need to be careful whenever you recharge your car’s air conditioner.

What Aircon Gas Is In Your Car?

What aircon gas is in my car
What aircon gas is in my car

R134a type refrigerant is the most common refrigerant in the automobile industry. Almost every car built since 1994 is equipped with an R134a refrigerant.

The three most common types of refrigerants we use in vehicles. And you need to know what type of Freon you need before you recharge your car’s air conditioner.

Here are the types of refrigerants :

  1. R12:
    R12 refrigerant is an old refrigerant type, and this is particularly efficient and cheap. In 1994, R12 type Freon was banned from all new cars sold in the US. R12 refrigerant is still a widely used refrigerant.
  2. R134a:
    R134a Freon is the most commonly used vehicle. R134a Freon may be in your car right now. Almost every car built since 1994 is equipped with an R134 refrigerant.
  3. R1234yf:
    This is the new type of refrigerant in the automobile industry. R1234yf was chosen to replace R134a in all new cars by 2021.

Car manufacturers in other countries already use this refrigerant instead of R134a. So, R1234yf refrigerant will be the most used Freon in the vehicle.

Frequently Asked Questions (FAQs)

How much does it cost to refill Freon in car?

Refilling Freon cost depends on your car model and make. The average range of refilling cost of Freon is about $130 to $300.

You have to be certain before refilling Freon’s in your car because excessive Freon in the car air conditioner can bring some issues in your car.  That’s why you should check the Freon level in your car.

How much Freon does a car hold?

A car’s Freon holding capacity is reducing day by day. Typically a car has only 14 to 28 oz refrigerant storage capacity.

Freon comes in cans; that’s why you buy refrigerant cans from the store. An R-134a Freon can hold only 12 oz. So, one Freon can should be enough for your car.

Cost of Freon per pound for car AC?

Air conditioner Freon or refrigerant price changes every year based on region and state. R-134a Freon is used for a car.

Now per pound of Freon costs you between $50 to $120. And Freon replacement cost will be high for your car. Freon replacement costs between $170 to $250 at the garage.

How long does Freon last in a car?

Car air conditioner runs less than a home air conditioner. And if you are living in a cold area then using the car air conditioner will not be that much.

Car Freon lasting depends on your use. The more you use a car air conditioner, the more Freon will be used. Typically a car air conditioner Freon lasts at least three years.

How often does Freon need to be replaced in car?

Replacing Freon depends on your use of the air conditioner and the current condition of your car A/C. The automobile mechanic’s recommendation is to replace Freon every two or three years in the car.

Many car owners replace Freon unless there is a leak; that is not a good practice.

If you don’t want to bring any issues to your car’s air conditioner, you should check the Freon in the car and talk to your mechanic to replace Freon whenever it’s needed.

Final Thoughts

Every car needs Freon recharge. Knowing the Freon level in the car is important to keep your car maintained well.

Checking the Freon level in the car also helps you to avoid great damage to your car air conditioner. You can check Freon in a car with gauges and also without gauges.

To tell if your car AC needs Freon is not that hard to notice. Car air conditioner blows hot air when your car air conditioner is on low Freon. This is the most common sign of low Freon in a car.

Freon leaks in your car, also a major issue to lose Freon consistently.

Without noticing the main reason why car air conditioners keep losing Freon, you cannot fix that problem. So you need to figure that out first.

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2 thoughts on “3 Steps To Check Freon Level In Car And How To Recharge A/C”

  1. Dear Meraj or any of Meraj’s respected colleagues;

    I have read your essay “9 causes car won’t start when engine is hot & what to do”. It is great and very helpful.

    My car’s starter does start the car very well when the engine is cold, e.g., in the morning.

    But after driving for 45 minutes or more, when the engine is hot, If I turn off the engine, for any reason, then I am trying to start the engine again, the starter does not turn (does not work).

    So I have to wait for 1 hour or more, until the engine cools down. After that, it can have a normal starting.

    What might be the most probable cause for this? battery connections? or the starter itself?
    I would appreciate it if you can help me to find that.

    Best Regards,
    Ali Aghagolzadeh

    • Hello, Ali
      I’m glad you find my articles helpful.

      As far as I can see, your car has overheating issue. When a car has an overheating issue, the vehicle shut off automatically after the engine gets to a high temperature.
      In most cases, the car’s defective cooling system causes the overheating issue. Now, your car’s cooling system can go bad for the lack of coolant and leak of coolant.
      Therefore, I recommend you perform a cooling system pressure test and ensure the coolant is not leaking. Also, flush the cooling system if necessary. These are the quick and simple solutions to prevent overheating issues in the vehicle.

      And don’t forget to tell me any updates on this issue.

      Best wishes,


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