What Causes Low Freon Levels in Cars? Recognizing the Signs

Why is it important to know the symptoms of low Freon in car? You need to know these symptoms because Freon is vital to the way your car’s air conditioning system functions. Your car’s air-conditioning system essentially relies on a refrigerant (Freon) to operate. How does this happen? Freon is compressed by a compressor in the AC unit, causing its pressure to rise while increasing its temperature. Hot Freon is then made to move through coils in the AC unit, reducing this temperature and turning it into a liquid.

The liquid Freon then moves through an expansion valve where it evaporates and is converted to a cold gas. In this form, the Freon then moves through a group of coils which absorbs the heat in your car and makes the cabin cool. Freon plays a crucial role in your car’s AC system, which is why you need to know how to tell if Freon is low in ac car.

Symptoms of Low Freon In Car

Symptoms of Low Freon in Car

When the Freon level drops, your car’s   AC unit won’t function properly. But that is not all that happens. The AC clutch will fail to engage since the level of Freon is too low for the compressor to pressurize. But that is a sign that might not be so obvious. The good news is that your car will exhibit other low refrigerant symptoms. Here are some of them.

  • Loss of Refrigerant while driving
  • Obvious leaks
  • Low gauge reading
  • Sight glass
  • Ac not blowing cold air
  • Clutch not engaging

how to tell if freon is low in ac car

Loss of Refrigerant While Driving

An abrupt loss of cooling temperature from your car’s AC vents while driving might be an indication that some of the pressurized Freon has caused a leak in the seals, hose, or fittings. When this happens, you will notice a white cloud-like emission from the area that is leaking. In some instances, you might also hear a hissing sound from the compressor, Also comes a Freon smell inside the car. 

Obvious Leaks 

 Visible freon leaks are a common symptom of low Freon in your car. Freon contains some oil that allows it to lubricate the compressor, so in its liquid state, it usually looks a bit like grease, only lighter. If you suspect a Freon leak, check the different components of your car’s AC system. Inspect the pressure lines, the service ports, the front shaft, the accumulator, the condenser, and the fittings that link with the compressor. If you notice something like a film or stream of liquid on these components, then you might have a Freon leak. To be sure, wipe off this film or stream, and if it appears again, then chances are that you have a Freon leak and the Freon levels are low in your car.  

Low Gauge Readings

One tip on how to check freon level in a car is to get the car AC pressure readings. You can do this once you know how to check freon in the car with gauges. Start by connecting an AC manifold gauge to the high- and low-service ports. Ensure that the gauge is well fitted by linking the red gauge hose to the high-side service port using a quick-release fitting. For the low-side service port, ensure that it is connected to the blue gauge hose. To get the correct readings, turn on the dials for the red and blue gauges when the car’s engine and AC are off. You should get a reading that is between 80-105 psi. When you take the same readings with the AC turned to the highest, the high side should read somewhere around 200 to 350 psi while the low-side should be about 25 to 35 psi. If the readings are lower than these, then your car is low on Freon.

Sight Glass

You could also tell if your car is low on Freon by checking on the sight glass (if your vehicle comes with one). This is a component that allows the viewer to detect Freon’s movement through the high-pressure line. When the Freon level is optimal, you will notice a clear fluid moving through the line. When the Freon levels are low, you will detect the presence of bubbles. If you don’t see any movement, then there is no Freon in your car.

AC Is Not Blowing Cold Air

A functional car AC unit with optimal Freon levels will blow cold or hot air according to what you set the AC on. One of the more obvious signs that the Freon levels in your car are low is a situation where the AC blows warm or hot air when you set it to blow cold air. This occurs because there is little or no Freon to pressurize and circulate within the system.

Clutch not Engaging

Your car A/C clutch causes the compressor to pressurize. You ought to notice a clicking sound whenever you turn on your car’s AC. That sound is the sound made when the AC clutch engages. The A/C clutch functions by detecting Freon levels. When it is unable to engage, the implication is that the Freon is much too low. It is also an indication that the car refrigerant is too low for the compressor to compress.

how to replace freon in car

Questions and Answer

Q: What Happens When Freon Is Low?

Ans: Whenever your car’s  AC system is low on Freon, the system’s evaporator coil becomes extremely cold. This causes the  Freon to flow back into its line. As a result, the surrounding moisture on the refrigerant line freezes up, causing the compressor to become icy while preventing the AC clutch from engaging.

Q: How Often Does Freon Need To Be Replaced In Car?

Ans: Not all AC units are built to have the Freon replaced, and in such cars, the loss of minute amounts of Freon does not hamper the function of the air-conditioner. However, the frequency of Freon replacement is dependent on certain things. Like when the AC no longer blows as well as it should. Other than that, since there is no stipulated maintenance procedure, you can change your car’s Freon annually. 

Q: Will Autozone Help With Freon?

Ans: Yes. Autozone offers a range of solutions for your car’s air conditioning system. Especially when you need to recharge your car AC, you can access some of these solutions online or offline.

Q: Is It Bad To Run AC With Low Freon?

Ans: Yes, it is. At least in the long run. Your car’s AC system will still function with low Freon. But its performance will be subpar at best. But if you don’t fix the issue ASAP, then there is the likelihood of the situation degenerating to the point of causing severe damage to your AC unit.

Q: Should I Recharge My AC Myself?

Ans: You can recharge your AC unit yourself if you know how to replace freon in car. However, you are better off letting qualified experts recharge your AC instead. This is because, in most cases, the low Freon is because of a leak and a technician is better suited to plug these leaks before recharging the AC.

Except you are a licensed technician, you will lack the training required to handle refrigerants, and you might not know the ideal amount to be restored into the AC unit. While there are many resources about how to recharge your car AC yourself, get a licensed technician instead.

Sign of Low Refrigerant YouiTube 

Final Words

Your car AC is at its best when the Freon levels are optimal. Knowing how vital the AC system is to your comfort, it is always important to keep the Freon at the right level. But how do you know if your car ac needs recharged? It is simple, just lookout for any of the symptoms of low freon in the car described in the article. Once you have noted any of these symptoms, get a certified mechanic to check your car.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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