How to Pull Vacuum on Car AC (Explained)

How to Pull Vacuum on Car AC

Pulling the vacuum on your car AC is critical to guarantee any type of air or dampness that can harm the system, in the long run, flushes out to protect the driver.

There are significant reasons for a frozen AC system, which is brought about by the buildup of water. If by any opportunity you stump on the considerations of whether it is critical to pull a vacuum on Car Ac or not, you shouldn’t weaver than to make it happen in a hurry.

To take out a vacuum on a vehicle AC requires a couple of actual processes to haul out as much air or dampness away from the refrigerant system. Therefore, in this article, you will find out why you need to pull a vacuum on a Car AC and how to get it done without technical procedure.

Can You Pull Vacuum On Car AC?

Yes, pulling a vacuum on a car AC is possible, and it isn’t a technical procedure. With explicit instruction, even a dummy with little or no IQ (Intelligence Quotient) will pull a vacuum on a car AC without breaking a sweat.

For optimal performance of a Car AC, vacuuming allows the swift flushing process of any form of moisture and air found in the system.

Many elements like air, moisture, and humidity, which can sum up to be a big problem for AC performance, affect air conditioning. You must pull the vacuum for the good of you and the vehicle.

How to Pull Vacuum on Car AC

As stated earlier, you wouldn’t need a big brain to get this done, and neither do you need to be a technician to pull the vacuum on your car AC. Here is a process you should creep on;

Identify Your Service Ports

This is the first major step before any other things but as you know, there are ground rules that you shouldn’t overlook.

See these ground rules as a precaution to ensure you take your sight and actions with optimum caution to avoid causing further troubles or kicking your AC into greater danger.

These are my few ground rules:

  • At first, your car needs to be parked on a flat surface.
  • Keep your car off and the AC system also turned off
  • Get your gloves and protective glass. (Your eyes and hands also need to be protected)
  • Locate your manifold gauge.

(High and low service ports must be located). According to how the AC system design appears on the framework, the low service port is located amid the compressor and the evaporator while the large service port, which is larger, is between the expansion valve and the condenser. The high service port has an inscription H while the low has an inscription L

Hook the Manifold Gauges

After identifying the ports, it is time to connect the high and low service ports to the system. We need the gauge to have the linkage done because it plays the role of connecting the AC system with the low/high-pressure ports. Here is a quick procedure:

  • Ensure there is no space for air or leaks. This means the valves on the gauge are tightly closed
  • Carefully connect the red hose with the high-pressure port while the blue to the low-pressure value
  • The mid-yellow hose should connect to the car AC vacuum pump, which is where recharging takes place.

Connect the Gauge to the Systems

This I regard as one of the defining moments of vacuuming your Car’s AC. How much vacuum to be pulled out of your automatic AC system needs to be determined, to do this follow these processes delicately.

  • Carefully have the blue gauge connected to the low-pressure service port. To ensure a fix, it will require a pushdown. The knob is done with a snap on the service port. Shake the hose gently to determine if it snapped the wrong way.
  • Have the red gauge go through the same step, but this time with the high-pressure service port.
  • Unlock the jointed manifold hose from both the high and low-pressure hose. Have it inspected, it should read “0”, which means the air is absent in the system.
  • Connect the yellow line to the car AC vacuum pump. This will only require using the seal to ensure it is tight enough for this connection.
  • Recycle your refrigerator. You want to reserve the option to do this without violating the law. You can recycle it yourself or conceivably take it to a carport to get it done, which I view as the best move as a safety precaution and to avoid polluting the environment.
  • Have the lines crosscheck, the blue, red, and yellow to be sure they are connected and opened up appropriately

Engage in the Vacuuming Process

Switch on the vacuum pump. Afterward, ensure the reading is “0”. Open the blue and red valves on the gauge. If done, the gauge needle should be below the zero readings, while the blue gauge stays below 30 inches. This is the best reading for the procedure.

Let it pump on a 30-minute sprint, close the red and blue valves on the manifold gauge, and allow them to take an hour’s rest.

This is to detect if there is any leak or not. If after 1 hour the blue still reads 30, it shows there isn’t any leak in the system.

After you’re sure of no leaks, take the vacuuming process for the next 45 minutes. Have the vacuum pump switched on with the gauge valves opened as well?

This process will ensure that it flushes out the moisture and that the system is dry and clear. After all, the process is done, have the valves turned off and also switch off the vacuum pump.

When it is looking okay, the next move is to recharge the air conditioning with the needed refrigerant.

How Long Should You Pull Vacuum On A Car AC System?

It shouldn’t take an eternity before the process is completed. With a time range of 45 minutes to 1 hour, you can pull a vacuum for your car’s AC provided there isn’t any form of leaks, and this time duration can send out as much moisture as possible away from the system.

How Can I Vacuum My Car Without Vacuum Pump?

The majority use the vacuum pump because everyone recommends it, but if you don’t have a vacuum pump or you find the process tiring, you can also do without a vacuum pump and still flush out moist air away from your AC system.

To vacuum your car without a pump will require installing access valves on the low-pressure valves and also on the high-pressure valves. Here’s a procedure you can note down:

  • Install the access valves on the refrigerant lines.
  • Have the high-pressure line depressed on the AC while you observe the low-pressure line. Ensure you check properly until when the high-pressure valve is at the lowest point and then switch off the vehicle.
  • Have the low-pressure side recharged to 10PSI and ensure there is equal pressure at both lines.
  • Take the first three steps again
  • Have the AC system recharged

Does Pulling A Vacuum Remove Refrigerant?

Yes, pulling the vacuum from the cooling system will remove the refrigerant but ensure you pull after recycling the refrigerant.

If you pull refrigerant with a vacuum pump, it will only cause damage to the pump. It can be done, but you shouldn’t do it. Instead, get a refrigerant recovery machine to get the job done.


Pulling the vacuum of your car’s AC is important to ensure the AC of your vehicle is functioning at all times. You could do this with a pump or get your hands tied to installing access valves to refrigerator lines.