How to Vacuum Car AC System Without Pump

If there are leaks in the system, the refrigerant gas contaminates the environment and causes the air to become stale.

This situation is likely to cause respiratory diseases or allergies in the passenger compartment as a result of bad odors.

In this article, I will show you how to vacuum car ac system without pump, let’s get down to work.

Why Should You Clean Your A/C?

When we talk about cleaning the air conditioning system, we mean sanitizing the ventilation ducts, including the evaporator inside.

The liquid refrigerant changes its aggregate state from liquid to gaseous and requires energy for this change of state. This energy is taken in the form of heat from the air drawn in by the air cooling system.

The condensate drip pan at the back of your refrigerator can be a breeding ground for fungi and bacteria.

The evaporator absorbs heat from the air to evaporate the refrigerant and cool the incoming air.

This generates a significant amount of condensed water in the evaporator, which can usually be drained through a hole.

Fungal spores and bacteria grow in the evaporator, as well as in the vents, resulting in the characteristic musty odor of an air conditioner.

The most important thing is your health and that of the vehicle’s passengers, as the ventilation system throws the fungal spores directly into the face of the driver and passengers.

Disinfection of the air conditioning system is usually performed as part of air conditioning maintenance, which should be done every two years.

It is also suggested to replace the cabin air filter, commonly known as the pollen filter, every time it is cleaned.

How to Vacuum Car AC System Without Pump

Step 1: Depress the AC system’s access valves.

It will be necessary to install access valves on both the high and low sides of the compressor to allow proper operation.

The next task is to close the high-side access valve and specify compressor pressure on the low side.

Pressure will build up to the point where the high side valve will close, thus shutting down the compressor.

Step 2: Charge the low-side valve

Now is a good time to adjust the low-pressure side of the A/C to 14 psi. Running the friction for a few minutes will bring the pressure on the high and low sides close to equilibrium.

Step 3: Disconnect pressure from the high side valve.

You can now turn the compressor behind the service valve and push it against the high valve to achieve the desired effect.

Close the high valve and the compressor until the low-pressure side reaches operating pressure.

Step 4: Repeat Steps 2 and 3.

Now, for the next three minutes, you must continuously adjust the machine pressure to 14 psi and equalize the pressure in the machine.

Next, you must “turn on” the compressor by depressing the valve on the high-pressure side of the compressor.

If no vapor, air, or moisture is expelled through the high-maintenance valve during this procedure, the valve should be closed.

The vacuum mechanism is almost completely finished by the AC system, which does not need a pump.

Step 5: Charge With Refrigerant

The last step is to pump the refrigerant into the air conditioning system. The amount of refrigerant needed is indicated in the instruction manual or in the appliance owner’s manual.

When you have finished introducing the refrigerant into the air conditioning system, turn off the compressor.

How to Vacuum Down and Recharge an Air Conditioner?

You have two options for charging your car’s air conditioner. The first method involves introducing a small volume of refrigerant to charge the system, while the second involves injecting a vacuum and charging from the ground.

However, since the second alternative requires the use of a vacuum pump, it will not be discussed in this report.

Failure to clean dust and moisture from inside the AC system may affect the performance of the apparatus. Instead of waiting for a crisis to arise, you can vacuum on a daily basis.

In fact, most manufacturers suggest that you clean the machine after each operation. This helps remove residual moisture, thus extending the life of the compressor.

Follow these steps to perform a quick refrigerant recharge of your vehicle’s AC system.

  1. Safety instructions. Until it is time to start the car, park it on a flat surface with the engine off. In case of emergency braking, stop at the gearbox and wear safety glasses and gloves.
  2. Purchase a basic charging package. It can be purchased from your nearest car dealer.
  3. Remove the valve seat protection mechanism before starting the engine.
  4. Find the low-pressure side device service port on the larger of the two refrigerant sides. These positions can change and blur.
  5. Remove the dust cover from the low-pressure side service port until you have located it.
  6. Pull up on the retaining ring when pressing the valve into the inlet port. It is important to remember that the low-pressure side connector would not work on the high-pressure side port. This tends to avoid misunderstandings.
  7. After installation of the replacement kit, the pressure gauge would show the state of charge on the low-pressure side of the system.
  8. Start the engine after securing the kit, and turn the air conditioner on at maximum level, including fan speed.
  9. After waiting 30 seconds, the compressor will start running. After this, there will be a pressure drop.
  10. To allow the refrigerant to enter the unit, press the plunger valve inward. Then release it. The pressure gauge will rise, indicating that fluid has been transferred from the can to the reservoir. The pressure gauge will decrease again after the plunger is released.
  11. Repeat this procedure until the device pressure is correct. This will show on the gauge. Do not overfill the canister.
  12. As the pressure increases monitor the temperature of the evaporator outlet tube and the passenger cabin breather ports. Both may feel cold to the touch.
  13. Turn off the ignition. This can shut off both the air conditioner and the pump.
  14. To release the unit and cover the service port, pull up the base charge pack bracket.
  15. Replace the service port dust cover.


Does vacuuming your AC system remove oil?

You may be curious to know if draining the device requires the replacement of the PAG gasoline. A vacuum cleaner cannot remove oil from the system. It should not be necessary to inject oil until the accumulator or compressor is disconnected.

Do you have to vacuum an air conditioning system in a car?

To avoid complications caused by air or moisture in the A/C line, consideration should be given to installing an evacuation device in the vehicle in addition to the house.

In addition, air or moisture in the vehicle air conditioning device can always be evacuated before charging the refrigerant.

What happens if you overcharge your AC?

Overcharging or using too much refrigerant in the air conditioner will cause damage to the compressor.

Excess refrigerant will build up in the compressor, causing the temperature to drop below average. It may even flood the compressor, causing mechanical parts to fail.

Rapid discharge temperature, natural overheating, high compression ratio, high condenser pressure, and overcooling are some of the most typical signs of excess refrigerant.

How often should you vacuum your air conditioning system?

Experts usually recommend servicing the air conditioning machine once a year. To avoid damage, use a vacuum cleaner to remove moisture or air from the piping.

Each year, spring is the right time to service your air conditioner. Although most maintenance tasks can be performed by yourself, if you encounter any major problems, contact an authorized specialist.

Final Thoughts

After reading this article, you will learn how to vacuum car ac system without pump. Vacuuming the air conditioning system is the most common and beneficial operation.

Remember to follow the instructions and if you successfully repair the vacuum system, feel proud of yourself.

Knowing how to do it yourself will save you time and money, as you won’t have to take it to an expensive mechanic when you can do it yourself.

Liam Dare

As CEO of, my passion for the automotive world motivates me to build online businesses that provide information and entertainment to users. I am proud to contribute in a positive way to the automotive community.