How To Pull Vacuum On Car Ac?

Have you ever turned on your car’s air conditioning only to feel warm air coming from the ventilation system? It is unsettling and annoying, yes? Such system failure is caused by moisture or trapped air. As a result, it’s crucial to remove any trapped air from the air conditioning system. Therefore, you must vacuum the AC system to prevent a breakdown of the system. In this article, you will learn about how to pull vacuum on car Ac?

Systemic trapped air not only reduces the cooling program’s effectiveness but also speeds up system failure. This post will therefore go through the rationale for and specifics of vacuuming an automobile air conditioning system.

Purpose of Vacuuming:

The following are the justifications for vacuuming your AC systems:

Remove undesirable contaminants:

Pulling a vacuum on the air conditioning system is crucial, particularly after replacing a damaged AC compressor as well as a condenser. An air conditioning system should be vacuumed to get rid of any unwelcome impurities.

The vacuum pump can be useful here. You can remove these impurities as well as the trapped air and moisture from the system by pulling a vacuum.

Maintaining System Cleanness:

The vacuum pump’s primary purpose is to remove air that is trapped and moisture within the air conditioning system, as we’ve explained numerous times throughout the essay. This is done to avoid the system becoming more humid.

If neglected, the system’s air conditioning may turn into a haven for mold and mildew. When that occurs, the air conditioner’s heated output will be the least of your worries.

Prevent System Failure:

The primary reason you shouldn’t disregard performing a vacuum in your car’s air conditioning system is to avoid a system malfunction.

It would result in a mechanical failure of numerous components if you didn’t routinely vacuum your car’s air conditioner.

Failure to pull a vacuum will also result in decreased system effectiveness, corrosion, as well as rusting, and eventually system failure.

How to pull vacuum on car ac?

Before figuring out how long to clean a car AC system, let’s have a look at some simplified vacuuming techniques.

How To Pull Vacuum On Car Ac?

As previously said, if you don’t remove the vacuum from an air conditioning system, performance will suffer. I advise performing a periodic vacuum on your air conditioning unit.

Do not wait until issues arise. Let’s go over all the do-it-yourself steps required to remove a vacuum from an AC system.

Starting up and identifying low- and high-service ports:

In your garage or driveway, park your car on a level surface. Check your local laws before vacuuming the AC on the driveway to prevent breaking any rules. Turn off the AC and don’t start the car yet.

Put on your working gloves and safety eyewear. Find the high and low service lines.

An H and L are inscribed on the high service port and low service port, respectively. Track down the refrigerant lines. They follow the service ports on the compressor and are coupled to it.

Hookup gauge connection:

Holding up a gauge set comes next after finding the service ports. To connect the system’s low and high service ports, you require a manifold gauge. In addition to vacuuming and charging the system, you’ll use it.

Make that the fittings and hose are leak-free and that the connections are airtight. Make that the gauge’s valves are in the closed position.

The low-pressure side is represented by the blue hose, while the high-pressure side is represented by the red hose.

You’ll subsequently recharge the system there, thus the middle yellow hose needs to be connected to the car AC vacuum pump. Before attaching the gauge valves to the air conditioning system, close them.

Connecting gauges to system:

Connect the low-pressure service port of the blue gauge. To fix it, turn the knob until the hose connects to the service port, then release. Check to determine if the hose snapped improperly by wriggling it.

To attach the red hose to the high-pressure service port, remove it from the manifold gauge. To do it correctly, repeat the same procedure on the low-pressure line.

On the high-pressure hose as well as the low-pressure hose, unlock the gauge manifold hose. Examine the manifold gauge’s gauge. There should be no air in the system; hence it should be set to “0.” Next, attach the yellow line to the vacuum pump for the vehicle’s air conditioning.

The hose just requires a hand-tightening amount of tension. A plier will suffice to do the task for you. There is a seal that will do the trick with additional hose connections by hand.

You don’t have to release Freon into the atmosphere in order to break the law in your community. These refrigerants have detrimental effects on the environment.

Verify that the blue, red, and yellow lines are all connected and open by crossing them all. If you’re wondering whether it’s possible to vacuum an AC system without pumps, you can, but the results won’t be great. Let’s go on to the following phase.

The action of vacuum:

Switch on the vacuum pump to begin the vacuuming process. Verify the manifold gauge’s gauge. It ought to be in the number “0.” On the blue and red sides of the gauge, open the valves. The gauge needle should decelerate and drop below zero. The blue gauge should gradually decrease to 30 inches, which is the desired level.

To close the valves red and blue on the manifold gauge and leave them idle for approximately an hour after allowing the pump to operate for about 30 minutes. This procedure checks to see if the system has any leaks.

After the waiting period, if the blue gauge needle remains at 30, it means the system is not leaking. Continue vacuuming for a further 45 minutes after confirming there is no leak. Open the gauge valves and turn on the vacuum pump.

This will remove all of the air and moisture from the system, leaving the interior completely dry. You can focus on something else while the pump works on its own. After 15 minutes, turn off the gauge valve and vacuum pump.


Can you create a vacuum on the low side alone?

You can, of course, only draw vacuum from the low-pressure line. The cooling system is always in operation. The orifice tube, one of its parts, limits but does not stop the flow of refrigerant. Vacuum removal from just the low side will still be effective.

Is oil removed by vacuuming the AC?

Vacuum pumps lower the refrigerant pressure, causing the refrigerant to transition from a liquid to a gaseous condition and leave the system. They aren’t intended to drain oil. In other words, they are unable to raise oil from the compressor or uphill.

How long should you vacuum a car air conditioner?

If there is no leak in the AC system, it typically takes 45 to 1 hour to draw a vacuum. This amount of time is sufficient to remove moisture and air from the system.

Leave a Comment