Have you got in your car and switched on your AC system only to receive warm air from the vents? It is unnerving and frustrating, right?
Trapped air or moisture causes such malfunction in the system. Therefore it is important to evacuate trapped air in the air conditioning system. So, to protect your air conditioning system from breakdown, you need to vacuum the AC system.
Trapped air in the system affects not only the efficiency of the cooling system but also causes premature breakdown. For this reason, this article will discuss reasons for pulling a vacuum and how to pull a vacuum on a car AC system.
Understanding the Importance of Vacuuming Your Car AC
Before diving into the steps, it’s vital to understand why pulling a vacuum on your AC system is necessary. When you service your AC system, whether by replacing components or simply recharging it, air and moisture can inadvertently enter the system.
Air contains oxygen and nitrogen, which significantly reduces the system’s efficiency, while moisture can lead to acid formation and contaminants within the refrigerant.
Strong reasons to pull a vacuum include:
- Elimination of Moisture: Prevents the formation of acids that can damage internal components.
- Air Removal: Improves system efficiency and enhances cooling.
What Is The Purpose Of Pulling A Vacuum?
Here are the reasons you should vacuum your AC systems;
Eliminate unwanted contaminants
Do you have to pull a vacuum on a car AC? It is essential to pull a vacuum on the air conditioning system, especially after replacing a faulty AC compressor or condenser.
The purpose of vacuuming an air conditioning system is to remove unwanted contaminants from the system.
Keep the system in a clean environment
Pulling vacuum from the air conditioning system involves evacuating moisture and air from air conditioning and refrigeration systems.
Pulling a vacuum from an AC system is done to eliminate harsh substances from the system. And to ensure the system runs in a clean environment.
To prevent system premature breakdown
If you ignore to vacuum your AC system, it may lead to a mechanical breakdown on the compressor and expansion valves. Other issues it’ll project include refrigerant line restrictions, lower efficiency, premature corrosion, and ultimate system failure.
To save your air conditioning system from the outlined issues above, you need to vacuum the system regularly. Most especially during system refrigerant recharge after installing a new AC component.
Tools and Equipment Needed
Before starting the vacuum process, gather the necessary tools and equipment:
- Vacuum Pump: Essential for removing air and moisture.
- Manifold Gauge Set: Helps monitor the pressure in the AC system.
- Refrigerant Scale: For weighing refrigerant to ensure proper charge.
- Safety Gear: Gloves and goggles to protect yourself during the process.
Step By Step Guide On How To Pull Vacuum On Car AC System
When you fail to vacuum the dust or moisture from within the AC system, it may deteriorate in terms of performance. Never wait for the problem to creep in, instead maintain the cleaning periodically for the AC to keep running.
Let’s get deeper into the DIY process that can help you in implementing the cleaning process without much expenditure.
#1. What you’ll need.
- AC Manifold gauge set: This essential tool measures system pressure and allows you to connect the vacuum pump.
- Vacuum pump: This powerful device removes air and moisture from the AC system.
- Refrigerant hoses: These hoses connect the vacuum pump and manifold gauge set to the AC service ports.
- AC service port caps: These caps protect the service ports when not in use.
- Safety glasses: Always protect your eyes when working with pressurized systems.
- Gloves: Wear gloves to protect your hands from refrigerant and other fluids.
#2. Identifying service ports.
To begin with, park your car in a garage or anywhere, where the surface is flat. Do not start the car or the AC system within.
The high-service port is larger than the lower counterpart. It is positioned amid the orifice tube and the expansion valve and the condenser.
When you follow the AC’s compressor linkages to the bottom of the car, a nozzle would be visible.
This very nozzle is the low-side service port that is stuck amid the compressor and the evaporator.
Now the real work to vacuum the AC system car can start.
#3. Hooking up the manifold gauge.
Once the identification of the ports is done, you need to hook up the manifold gauge. These sets of gauges facilitate the linkage between the AC system and the low/high-pressure ports.
Firstly, connect the vacuum pump’s hose to the low-pressure port present on the manifold gauge. This is the port that lies between the two gauges present on the gauge set.
Next, you need to connect the red-colored valve to the high-pressure port and the blue-colored valve to the lower one. It is the yellow valve that signifies the connection to the vacuum pump.
One thing straight, remember to keep the valves in the closed position before connecting to the AC system.
#4. Making the connections.
So now, let’s move on to learn how to pull vacuum on car AC and how much vacuum to pull on auto ac system.
Get a hold on the right pressure port, and connect it to the gauge by merely lifting the connector ring in an upward direction and then pushing it in a downward direction.
Next, you need to turn the red valve in the clockwise direction to activate the service valve, located beneath. Repeat the underlying step for the low port as well.
Once all the connections are secure and tight, it becomes essential to taunt the small valve which, in turn, activates the internal plunger.
This plunger facilitates the actuation of the port valve to refrigerant lines. When concerned as to how to vacuum AC system without pump, one should know that it is possible but would not be that efficient.
#5. The vacuuming action.
Make sure the readings on both gauges are “zero.” Move on with connecting the other end of the yellow hose on the gauge to the vacuum pump.
Now, turn the pump to the “ON” position. Vacuum pressure should be tracked and should reflect up to 27 Hg or aptly 29 inches.
When concerned as to how long to vacuum AC system, you should know that it would take around 30-45 minutes. This is enough time to get rid of moisture and dust inside the AC system.
For effective vacuuming, open the low port’s valve of the gauge. Once, the tenure of vacuuming has ended; close the low-pressure valve and now you may switch off the pump.
The gauge should be reading pressure around 27-29 inches. If the reading goes hay wired, there is a potential vacuum leak. Contrarily, if everything is fine, you can detach the vacuum pump car AC and place the hose in a refrigerant.
Start your car, turn the AC on, and open the low-pressure valve that is present on the gauge in a slow manner. This step is undertaken to ensure a constant flow of refrigerant into the AC.
Put the caps and the hood back on. And, you are done! You could also go through maintenance tips for the procedure for discharging AC at home.
What Happens If You Don’t Pull A Vacuum On An AC System?
You should ideally vacuum the AC system to help remove any moisture buildup. Leaving it could cause long-term damage and cause the AC to freeze over.
Additionally, it increases the condenser pressure and temperature. The battery might drain more rapidly. The last thing is the damaged AC compressor.
By running the vacuum over the component, you will be removing some of the moisture and air, while reducing the pressure.
Any pressure or moisture should boil away with the ambient temperatures created by the vacuum, which completely cleans the unit and makes it functional. Now, you can add your refrigerant to ensure your AC works and keeps the car cool when activated.
Common Mistakes to Avoid
When performing this procedure, several mistakes can cause issues within the AC system. Avoiding these can enhance the longevity and efficiency of your vehicle’s AC:
#1. Neglecting Leakage Checks.
- Always ensure that any potential leaks have been addressed before pulling a vacuum. Ignoring this could lead to repeated vacuuming and recharge cycles.
#2. Overcharging the System.
- Make sure to adhere to the manufacturer’s specifications regarding refrigerant amounts. Overcharging can lead to compressor damage and reduced performance.
#3. Using Non-Compatible Refrigerant.
- Ensure that you use the correct type of refrigerant for your vehicle. Using the wrong type can lead to damage and inefficiency in the AC system.
How Much Does It Cost To Pull A Vacuum On AC System?
The costs should be in the range of $200. However, certain situations spike the costs closer to $300.
The additional costs are often labor-related and checking all the systems can be labor-intensive. Many people often have to dole out an additional $150 for the labor cost.
The great thing about vacuuming your AC is that you can do it at home when you have the vacuum. Unfortunately, these tools can be very expensive.
FAQs.
Q: How long should you pull a vacuum on a car AC system?
Now that we know how to pull a vacuum on car AC, how long does it take to pull a vacuum from a car AC system?
It takes an average of 45minutes to 1hour to pull a vacuum from an AC if there’s no leak in the system. This is enough time to expel moisture and air out of the system.
When vacuuming deep moisture, consider replacing the AC receiver or accumulator. This will help to keep moisture under check.
Q: How do you get the air out of a car AC without a vacuum pump?
While the most general way of vacuuming the air out of an AC system is using vacuum pumps, you can still pull vacuum without a vacuum pump. Refrigeration and air conditioning systems function with refrigerant and oil circulating in them.
Any other substance is unwanted and should be expelled out of the system. Whether it’s oxides, moisture, debris, or air, you need to pull it out.
While using vacuum pumps is the best method for evacuating air from the air conditioning systems, there are other alternatives. The best alternative requires installing access valves on both low and high-pressure valves. Here are the steps to follow;
- Install access valves on the refrigerant lines.
- Depress the high-pressure line access valve on the AC and observe the low-pressure line. Once the high-pressure access valve gets to the lowest point, close it and switch off the car.
- Recharge the low-pressure side to about 10 PSI and ensure the pressure on both lines equalizes.
- Repeat the first step.
- Repeat steps 2 and 3.
- Recharge the AC system.
Q: Can you pull a vacuum on just the low side?
Of course, you can pull vacuum from only the low-pressure line. The air conditioning system runs continuously. It has a component called the orifice tube, which restricts refrigerant flow but doesn’t stop it. Expelling vacuum from only the low side will still work.
Q: Does pulling a vacuum remove refrigerant?
Pulling vacuum from your cooling system removes refrigerants. However, only pull vacuum after recycling the refrigerant.
Using the vacuum pump to pull refrigerants will only damage the pump. They’re only designed to evacuate moisture. If you want to pull refrigerant with a vacuum pump, don’t do it. Instead, get a refrigerant recovery machine.
Q: Does vacuuming AC remove oil?
Vacuum pumps reduce the refrigerant pressure and cause it to change from liquid to gas state and expel out of the system. They are not designed to remove oil. In short, they can’t lift oil uphill or from the compressor.
Q: How much vacuum should an AC system hold?
An AC system needs a vacuum of about 500 microns or 29.92 hg gauge pressure to successfully remove any air, moisture, debris, or oxides that made their way into the system. An air conditioning system can hold 29.92 hg for a minute or more.
Final words
We’ve provided sufficient information on how to pull vacuum on a car AC and why you need to vacuum the AC system. With the above instructions, you can do this on your own.
After successfully vacuuming your AC system, pat yourself on the back. Wait! Do not forget to give us some credits. This has saved you an expensive service fee that you would have given to an HVAC technician.