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How to Pull a Vacuum on a Car Air Conditioner?

Imagine you got into your car on a hot summer day and felt frustrated when you turned on your car ac and received warm air from the vents. It may be due to moisture and trapped air with unwanted contaminants.

Professionals suggest using a vacuum pump to pull a vacuum on your car’s AC but there is another way to pull a vacuum from the car’s AC system. If you don’t know about these procedures don’t worry; I will tell you how to pull a vacuum on a car air conditioner. So if you want to clean your AC, read the full article.

Car AC Vacuum issue

Suppose you come from outside in your car on a hot summer day, and seeing your AC not giving enough cool air will make you feel crabbed. So let me tell you how to resolve this problem.

Try to resolve this issue with all your focus; otherwise, it can become a reason for the car alarm keeps going off. Let’s disclose all the DIY procedures required to pull the vacuum from the AC system.

Vacuuming a car AC with a vacuum pump

Try to park your car on a flat surface like a driveway or garage. Make sure to check your local law before starting the process to avoid violation.

  • Use Protective gloves and glasses for safety. 
  • Find the low and high service lines.
  • The low-service has L, and the High-service port has H written for identification.
  • Then you have to find the refrigerant lines (These lines are attached to the compressor).
  • Then you have to track the service port on the refrigerant lines.
  • Then hold up a gauge set.
  • Take a manifold gauge, as it can be used for vacuum and recharge purposes and in connecting the low and high service ports to the system.
  • Make sure there is no leakage on the hose and fittings.
  • Make sure to check the valves on the gauges are closed.
  • Close all the gauge valves before connecting them to the AC system.
  • Determine how much vacuum you want to pull from the auto AC.
  • Attach the low-pressure service port with the blue gauge and fix it.
  • Attach the red hose with the high-pressure service port and fit it.
  • Unlock both the low and high-pressure manifold gauge hose.
  • Make sure the system has “0” air in it.
  • Then connect the car AC vacuum pump with the yellow line.
  • Again check all the coloured lines are correctly connected and opened up.
  • Turn on the pump and open the valves on the red and blue sides of the gauge.
  • You will see the needle is 30 inches dragged down in the blue gauge.
  • Run the pump for 30 minutes, then close the blue and red valves on the manifold gauges.
  • Wait for an hour and then check if the needle is in the same position; then, there is no leakage in the system.
  • Open the gauge valves and switch on the vacuum pump for 45 minutes until it dries inside.
  • Turn off the vacuum pump and the valves on the gauges after 45 minutes.
  • It’s done; you can charge your AC with the recommended refrigerant and enjoy the Cool air from your clean AC.

Vacuuming a car AC without a vacuum pump

If you are unfamiliar with pulling the vacuum with a vacuum pump, you can use this procedure to vacuum your car’s AC system.

Follow these steps to vacuum the AC system without a pump.

  • The first step is installing access valves on the refrigerant lines.
  • Observe the low-pressure line while pushing the high-pressure line access valve.
  • Switch off your car and close it once you see the high-pressure access valve reaches the lowest point
  • Revive the low-pressure side to approximately 10 PSI.
  • Make sure the pressure balances on both sides.
  • Then you have to repeat the 1st, 2nd and 3rd steps.
  • Now Recharge the AC system with the recommended refrigerant.
  • Enjoy; your problem is now solved.

Safety Precaution

Before Cleaning the AC system of your car, make sure your car AC don’t have refrigerant. In any case, if you have any refrigerant in your car AC, then go to any garage and recycle it. As refrigerants cause severe effects on the environment so, releasing them is against local law. You can visit offroadscare if you want to know more about vehicles, vehicle issues, and other informational stuff.   


You will feel frustrated when you come to your car on a hot sunny day and your car AC is not working well, so what can you do? The first thing that comes to your mind is to fix this issue. Usually, an easy way to vacuum a card AC is through a vacuum pump, but you can also do it without a vacuum pump. It’s your choice to choose any procedure, but make sure to clean the AC if it has any refrigerant. Releasing refrigerants by yourself is just like installing a car alarm by yourself, as it can cause Car Alarm Installation issues. So go to the nearest garage to release refrigerants, as releasing them in the environment is against the law.

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