Five Signs That Your Car's AC Conditioner Does Not Need Freon (and What to Do About It)

You rush to your car on a scorching summer day in the hope of finding some relief. In these moments, there’s nothing worse than having a car air conditioner that isn’t working right. Sometimes, the issues are just signs that your car’s air conditioner needs Freon. 

If the air isn’t blowing cold or the clutch isn’t engaging, it might be time for a recharge. Low Freon may also occur due to leaks. This can be detected by visual inspection of the gauges, or by inspecting the sight glass on equipped systems. 

In this article, we examine the various signs that it’s time to recharge the A/C. You will also learn how to fix the problem. We also provide an estimate of the cost to repair your system so that you are fully informed. 

Freon Needs to Be Installed in Car Air Conditioning

1. Breathing Warm Air

Air conditioning is essential for keeping the interior of the vehicle cool. When the system isn’t working right, you might first notice that the air becomes warmer or simply doesn’t get as cool as it once did.

The air will get hotter as there is less Freon. Freon can also cause this issue if the compressor or condenser is not working properly. 

Related: Car AC Doesn't Bloat Cold Air The Common Reasons

2. AC Clutch Doesn’t Engage

When the air conditioning system works as it should, the clutch engages to pressurize what’s inside the compressor. You know it’s happening because you hear the typical clicking sound that occurs when it’s engaged. 

The clutch might not work if Freon levels drop below a certain level. However, this problem is also common when there’s a blown fuse, a poor ground connection or a bad engine coolant temperature switch. 

RELATED: 5 Signs of a Bad AC Compressor Clutch (& Replacement Cost)

3. Leaking system

Low Freon is most commonly caused by air conditioning leaks. The oil in your refrigerant might cause you to notice the location of the leak. The oil can be seen on the surface in the form of grease or a lighter colored substance. You can check the pressure lines, condenser and fittings for any oily substance. You can wipe the oily substance off if you suspect you have it.

Of course, there’s always the chance that there was a more abrupt loss of the Freon. Freon may be lost faster if there are leaks in fittings, seals, or hoses. You may notice a cloud of Freon around the area where the leak is. If the pressure has been lost, it could also be heard hissing. 

RELATED: Does AC Stop Leak Sealer Work? (& Is it Bad?)

4. Low Pressure Gauges

When you perform basic AC checks you may notice that the system might be low. The manifold gauges should be connected to both the high- and low-side ports. 

Begin by turning off the engine and reading the gauges. When the engine is turned on and the air conditioner set to high, the low gauge might show a reading of 35-40 PSI, while the high side will register 200-335 PSI. Freon is required if you see anything below this. 

5. Low Vision Glass Reading

A sight glass is an option on some vehicles. If you have this setup, it’s simple to tell when the car needs more Freon. 

You can clearly see Freon's high-pressure side through the sightglass. Clear fluid flows freely along the line when it is at its best. If the system drops below a certain level, bubbles will form. If there’s nothing inside the sight glass, it’s safe to assume that it’s void of Freon. 

How do I recharge my car's air conditioner?

To fill your AC system, we recommend that you use a licensed workshop. Freon is bad for the environment and you can do very expensive damage to your AC system if you don’t have the knowledge.

If your car’s AC system is empty of freon, you need to make a leak check before refilling it. In some countries, it may be unlawful to recharge the system by yourself without the appropriate certification.

However, here’re some ways to do it.

1. Attach Recharge kit

You can quickly get Freon to the desired level with the right recharge kit in just minutes. The quick-connect connector attaches the hose to the AC port. Press down on the hose until it snaps into place.

You should not trigger the device yet. Otherwise, you will release the refrigerant from the car’s AC into the air. 

2. Add Refrigerant

Turn on the engine and check the gauges. The air conditioner should be turned on to its highest setting. The compressor should engage the clutch at a pressure of 35 psi. As much as possible, the reading should be near 40 PSI. 

The can of refrigerant should be attached to the rechargeable hose. Hold the can upright and squeeze the trigger for several seconds as the refrigerant enters the system. Release the trigger and check the pressure gauges to ensure you don’t overcharge it. Continue this process until you reach 40 PSI.

3. Take a look at the temperature

Once the pressures are in the normal range, it’s time to check your work. You can check your cabin's temperature by inserting a thermometer at one vent. If everything works properly, you should see a temperature reading of between 40-50 degrees Fahrenheit. 

If you still aren’t getting the right cabin temperatures, something else could be wrong. If you aren’t sure how to troubleshoot the car, you want to head to a professional where the compressor, cooling fan, condenser and electrical system can all be checked. 

How much does it cost to recharge your car's air conditioning?

The cost of parts and labor to recharge your car's air conditioner system will be between $125-$200. The service visit shouldn’t take more than one hour unless it’s packaged with other services at the same time.

Recharging your air conditioner system in your garage can help you save money. You can make a big savings by having the right tools at hand. The average cost to recharge your system at home is around $20-30. You may require the appropriate certification, depending on which country you are in. It is possible to cause irreparable damage to things if you do not have the correct knowledge.

RELATED: What Does an AC Recharge cost? Average by model