How To Bleed Off An Overcharged Car AC?

It’s possible to add more refrigerant to a car AC than needed, causing an overcharge. Bleeding the vehicle’s air conditioner can remove the excess product from the system. But how can you achieve this task? We researched to find the process for you, and here’s what we found.

Bleed an overcharged car air conditioner by using a typical automobile coolant recharging system. Upon acquiring that necessary equipment, follow these steps:

  1. Park the car and expose the engine while it’s still running.
  2. Attach the recharge kit without the refrigerant container to the appropriate terminal.
  3. Turn on the gauge on the recharge kit to remove excess refrigerant.
  4. Once the arrow points to the green area, press the handle on the gauge repeatedly to remove additional refrigerant.
  5. If the gauge's arrow is stable in the green area, check the car's AC if it's now producing cold air.

Take note that an overcharged car AC will generally show some relatively tell-tale signs that indicate the concern. Continue reading as we talk about the signs of a vehicle's air conditioner having too much refrigerant. We’ll also tackle the steps to bleed an overcharged automobile AC unit in greater detail.

Checking a car air conditioning system refrigerant recharge, How To Bleed Off An Overcharged Car AC?

What Happens If You Overcharge Your Car's AC System?

Overcharging a car’s AC can make the cooling system produce warm air, along with other concerns. The system becomes inefficient, causing those issues. If left alone, the problem can cause serious issues, such as creating irreparable damage to the air conditioner.

What Are The Symptoms Of An Overcharged Car AC System?

Pouring coolant


Car owners can check for certain signs that may indicate they added too much refrigerant to their vehicles’ ACs. Some of these symptoms are:

Frost Buildup

Adding more refrigerant to a car’s AC may increase the risk of it creating frost within and around the evaporator or lines. At first, the air conditioner may provide cold air. But the frost can block the condenser from converting warm air efficiently, resulting in the warm air blowing out of the vents.

Compressor Noises

Normally, a vehicle’s AC makes sounds because of the air coming out of the vents. However, one tell-tale sign of overcharging the car’s cooling unit is when it makes an unknown sound. In particular, the AC makes a weird buzzing or humming sound while it’s functioning.

Take note that a hissing noise may not indicate that the AC has excess refrigerant. 

Complete Shutdown

A car AC failing to turn on or if it shuts down suddenly can be a sign of overcharging. The excessive amounts of refrigerant increased the stress of the cooling system, snowballing its received wear and tear. The compressors will burn out over time if users don’t rectify this problem soon.

Overworked Engine

Generally, a typical automobile engine will last about eight years or 150,000 miles. Some vehicles possessing better engine technologies than their older counterparts may last about 10 years or 200,000 miles. However, overcharging the AC frequently may reduce those average lifespans.

Adding significant amounts of refrigerant into a car’s cooling system can result in poor fuel economy. Drivers may experience a loss of about five miles per gallon (MPG) or more. Engine power may also diminish by about 10 to 30 horsepower (hp) if the driver continues to drive with an overcharged AC.

Engine Overheating

Car engine over heat due to no water in radiator and cooling system


Since the engine becomes overworked because of the excess refrigerant, it can also be prone to overheating. A slight increase in engine temperature of about 20 to 40 degrees Fahrenheit may allow it to experience an engine knock. This phenomenon can lead to a cracked piston, melted spark plug, or destroyed piston ring.

If left alone for extended periods, the engine may enter a state called a ‘total meltdown.’ If this event occurs, most of the components in the engine block might become unusable. An expensive engine replacement will become necessary for the car to function normally.

Another problem that you may encounter is when the car’s air conditioner only works when driving. That issue may not come from the refrigerant but another source. 

How Do You Fix An Overcharged Car AC?

Checking the radiator antifreeze


You may only need a car AC recharge kit for this job. But before proceeding with this task, make sure that you consult your car owner’s manual. Some vehicles may require specific steps to access certain parts to make you bleed the refrigerant out of the AC.

Also, ensure that you practice proper safety protocols during the operation. For instance, wear safety glasses, long-sleeved clothing, and a good pair of work clothes. The extra layers worn can help prevent potential health issues, such as organ damage and respiratory problems.

After finishing the preparations, the following guide will help you reduce the refrigerant from an overcharged car AC:

Step-by-Step Guide

  1. Place the car in park while making sure it’s under a shaded area.
  2. Expose the engine by lifting the hood of the vehicle. Take note that the engine should be running.
  3. Wrap a towel around one of the car AC recharge kit's gauges to prevent the high temperature from harming the skin.
  4. Attach one of the cords of the recharge kit to the car's AC system. The location is where you'd typically add refrigerant to the vehicle.
  5. Turn on the gauge to bleed refrigerant from the car’s air conditioner slowly. Stop when the gauge’s arrow lands on the green area.
  6. Press the handle on the gauge repeatedly to bleed more refrigerant from the AC. Remember, stay away from the exhaust path to prevent skin damage.
  7. Watch the gauge for a few seconds without pressing the handle to ensure the gauge stays green.
  8. Go inside the car’s cabin and turn on the AC to check if it’s now producing cold air.

In some cars, you may only need to depress the Schrader valve to remove excess refrigerant from their ACs. However, if you don’t have the confidence or the skill to do this task, bring your automobile to the nearest car service shop. Avoid tinkering with your vehicle’s components without proper knowledge or self-assurance to avoid costly mistakes.

Check out this car AC recharge kit on Amazon.

Watch the video below to learn more details:

What Are The Symptoms Of An Undercharged Car AC?

Female hand checking the cooling of the air conditioner in the car


Car owners should know the difference between an overcharged and undercharged AC through the displayed symptoms. So here are some of the signs of a vehicle's air conditioner lacking refrigerant to help you identify the correct problem to fix:

Coolant Leaks

By itself, car refrigerant is a colorless gas. But many manufacturers use dyes to help users differentiate this product from other vehicle components. So, you’ll know if your automobile AC lacks coolant if a green or bright yellow liquid leaks from the system.

Disengaged Clutch

Many vehicles will have their clutches engaged with the help of the pressure provided by the refrigerant. A ‘Shift to Park’ message may appear on the dashboard’s display, preventing the vehicle from moving because of the low refrigerant.

Warm Air

Keep in mind that both overcharging and undercharging a car’s air conditioner can result in warm air blown by the system. Certain car AC recharging kits allow users to check the refrigerant levels of their vehicles. Another option is to use a digital diagnostics assistant to verify the existence of underlying problems.

Check out this car digital diagnostics tool on Amazon.

How Quickly Does Refrigerant Work?

Once applied, the car refrigerant should work almost immediately. But it may take about 15 minutes to two hours for the refrigerant to settle properly. Take note that a leak might be present if the product seems to take longer than usual to settle. Use a leak detector kit if the concern arises.

Check out this automotive leak detector on Amazon.

How Much Does It Cost To Recharge AC In Car?

Professional car AC recharging services cost about $150 to $300. Automobile repair companies generally base their prices on the make and model of vehicles. The overhead may also skyrocket if the automobile is particularly old.

Final Words

Bleeding an overcharged car AC is necessary to prevent additional issues from surfacing. Vehicle owners can use standard air conditioner recharging kits to accomplish this job. Another option is to have professionals recharge the car’s cooling unit, albeit with additional costs.

For more details on maintaining your AC system, check out our related posts: 

6 Best Hard Start Kits For AC Compressor

How To Pull A Vacuum On A Car Air Conditioner?

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