Updated at: 09-02-2023 - By: Sienna Lewis

Instructions on how to lubricate the air conditioner’s compressor would be greatly appreciated. Have you noticed that the compressor in your air conditioner seems to be getting oily, but you don’t know what to do about it? People usually oil their air conditioner’s compressor.
There may be a variety of routes to success, but are you confident that any of them will bring you to your end goal in this specific instance?
It’s tough to face after a long day at the office, and it’s usually the first obstacle you’ll face the next morning.
We can help you fix this problem quickly and painlessly so you don’t have to suffer through the heat when you’re already exhausted.
Of course, we don’t want that to occur, and we wrote this article for people just like you who are having problems. In order to resolve this matter, we will conduct more thorough research into the topic at hand. What follows is more information about the topic you’re interested in.

Putting Oil In An Air Conditioner Compressor

Numerous people are working to improve upon the various implementations of this strategy that are already available online. There is no need to spend hours on the road or even a few minutes driving to the nearest store.

Following these instructions will allow you to accomplish your goal. Since not everyone is willing to shoulder the burden of more strenuous tasks, we made it as easy as possible. To avoid harm in the event of an accident, it’s best to put on a protective suit before beginning any work.

This is for your own good. Remember this, as it is important. Keep them safe; you never know when they might come in handy. You need to get some sleep and get ready for tomorrow, whether it’s work or something else. In any event, here are the measures to take when putting oil into an air conditioner’s compressor:

Step #1. Removal of the compressor from the air conditioner.

If you want to work on your air conditioner’s compressor, you should get the right oil from a reputable company first. If you use the wrong oil, your air conditioner could break down on its own, wreaking havoc on its internal components without you ever knowing it was broken.

Locating the compressor and its cover is the first step in taking it apart. As a next step, unscrew the fasteners that were holding it in place. The compressor’s cover can be taken off without resorting to the use of a wrench, making maintenance much simpler. After that, you need to unwind the belt that can be seen inside the compressors.

Once the belt has been taken off For a risk-free oil change, you should disconnect the power cord from the appliance. Just grab it and pull it out of the machine, and it will come right off.

Finally, get rid of any pressure lines or other obstacles in the way of the air conditioner. At this point, you can remove the AC bolts. Once you’ve done that, remove them from the valve.

Step #2. Capturing and taking away the Freon

Even though it is highly recommended that you change the oil in your compressor, doing so is not mandatory. Connecting the reclaimer’s gauges to the area where you believe the Freon or refrigerant is located is the first step toward achieving this goal.
If the refrigerant leaks out of the system, it could have a serious effect on the environment, so it’s important to check every possible entry point.

Turn the machine on and make sure the gauges have all read zero before proceeding. After you’re done, make sure the machine is turned off and the valves are closed and unhooked so the refrigerant can’t escape.

Step #3. Add the compressor oil

A compressor needs to be removed with the help of screwdrivers in order to make any adjustments to the oil level. To avoid mishaps, take out everything from the machine, including the belts, wires, and lines.
You must then manually remove the compressor’s top. Drain the used oil from the machine into a container until it is completely depleted. When that runs out, grab a funnel and keep pouring oil into the opening. Replace the cap and make sure it can’t be easily removed this time.

Step #4. Reinstalling everything

Replace the condenser in its housing. Do not forget to use the wrench to make it as tight as possible. Feed the Freon into the machine, then turn it on. Set the wires where they belong, making sure they are firmly fastened.

How Much PAG Oil To Add To AC System

Air conditioners in automobiles are similar to engines in that they need a certain amount of oil to function properly.
To avoid an untimely breakdown, you should have a firm grasp on how much PAG oil is used in the air conditioning system.

Which AC Components Require an Oil Refill?

The air conditioner’s compressor is the part that requires adequate oil for optimal operation.

Unless you’ve modified the compressor or there’s a leak, you shouldn’t have to add oil to your car’s air conditioning system.

An adequate amount of oil is required for lubrication purposes in a compressor.
It uses a number of cylinders to apply pressure to the gaseous refrigerant, causing the gas to expand and generate heat and friction.
Oil controls the temperature of the system and decreases friction by making the moving parts more slippery.

Before adding the oil, make sure any leaks in the system have been repaired.
The system will soon require more oil, or else it may malfunction.

What Is PAG Oil?

Polyalkylene Glycol (PAG) oil is formulated for use in air conditioning compressors found in vehicles.

The R-134a refrigerant in the air conditioners requires a fully synthetic hygroscopic oil to lubricate the compressor.

It is important to use the correct viscosity oil in the air conditioning system, in addition to knowing how much PAG oil to apply.

In the case of PAG oil, there are designations like PAG150 and PAG VC-46 for each variety.

This is the PAG viscosity equivalent of a viscosity rating, such as 10W30, for conventional engine oil.

The owner’s manual will tell you what PAG oil viscosity the air conditioner’s compressor needs.

How much PAG oil should be added to the AC system?

Adding oil to the air conditioner may require following instructions for the compressor.
Check the manual if you think you’re putting in too much oil.

Most modern vehicles’ air conditioning systems need about 4 ounces (120 ml) of oil.

To avoid over- or under-filling the system and to be sure of the precise amount, testing the manual is recommended.

Overfilling can reduce the cooling cycle’s efficiency, and underfilling can cause compression failure.

The following is a breakdown of how much PAG oil is required by various AC parts:

  • Calculating Compressor Weight: 1.4 Oz.
  • Equals 1.5 ounces in the evaporator
  • One ounce of condenser
  • One ounce in the accumulator.
  • 1 ounce equals 1 hose

Before putting in oil or refrigerant, it is recommended to flush the entire system.

Always replenish the oil lost during a part replacement, whether you’re installing a new compressor or accumulator.

A compressor or battery, for example, may need to be replaced.
Any time oil is lost during the repair process, you should replace it.

No matter how much oil is added, the total will never go above the system’s oil capacity.

So, how much PAG oil should be added to the air conditioning system?
Keep the total amount to no more than 4 ounces at all times.
In whatever range your car’s air conditioning system operates.

Overview of HVAC Compressor Oil

The HVAC compressor has some moving parts inside of it. The mechanism can only run smoothly with a specific kind of oil. Oil also acts as a sealant for the compressor’s connections, preventing any leaks.

Both mineral oil and synthetic oil can be used in air conditioners. Later in this article, we’ll compare mineral oil to synthetic oil and talk about their respective applications and features. A word of caution: when servicing your air conditioner’s refrigeration compressor, be sure to use oil that is compatible with the refrigerant being used.

While it is the responsibility of your HVAC technician to determine which type to use, PickHVAC’s guiding principle is that the more the consumer/homeowner understands about their HVAC system, the less likely an inexperienced technician is to mess it up. It only makes sense to inquire:

  • What are you going to do to service or repair my AC (furnace, heat pump, air handler, etc.)?
  • What parts are you going to replace?
  • What are you going to replace them with (universal vs OEM, for example)?
  • What materials are you going to use (compressor oil, refrigerant, insulation, etc.)?
  • Are you sure the materials are specified for this unit? Do you have the right stuff?

Types of HVAC Compressor Oil

Lubrication is necessary for your air conditioner or heat pump compressor to keep it functioning smoothly as it works to make your home cool and comfortable.  It is imperative that the oil you use is compatible with the type of refrigerant that is in your HVAC system.   That is the key to the whole thing!

And that’s different from automobiles. Most can use either a standard or synthetic oil. Refrigeration compressors in HVAC equipment are not the same.

Below are the two types of compressor oil commonly used and any important information that deals with the function of oil in an AC unit:

Mineral oil – This type of oil, also known as MO or Naphthenic, is compatible with HCFC (hydrochlorofluorocarbons) refrigerants.   HFCF refrigerants are commonly referred to as Freon, even though that is a brand of refrigerant, specifically R22, which is outlawed for manufacture or import into the US because it depletes ozone if leaked or spilled.

Besides banned R22, other refrigerants safely used in compressors with mineral oil lubrication are:  R401A/B, R402A/B, R403B, R408A/B, R409A/B.

Synthetic oil – Synthetic oils are used in air conditioning compressors that use CFCs (chlorofluorocarbons) for the unit’s refrigerant.   This type of oil can be part of three different formulas, which will be listed below.   Synthetic oil is a newer product compared to mineral oil, and it keeps improving year after year. Each type of synthetic oil can work with a specific type of refrigerant.   Please note that there is some overlap between the types of oil. A small number of refrigerants can use either mineral or synthetic oil.

  • Alkylbenzene (AB) – This is a type of synthetic oil that has been around longer than most. The following refrigerants can use this type of oil in the AC unit: R22, R401A/B, R402A/B, R403B, R408A/B, R409A/B.
  • Polyolester (POE) – POE is used with refrigerants that are primarily CFCs.  It is the most-used type of oil in air conditioning compressors. Here is a list of refrigerant codes that can be used with Polyolester: R124a, R404A, R407A/C/F, R410A, R507A, R417A, R422A/D, R424A, R427A, R428A, R434A, R437A, and R438A.
  • Poly Alkyl Glycol – One the least common types of synthetic oil, it can be used in air conditioning systems that use CO2 and R744 for refrigerants.

There are some types of refrigerant that are compatible with both mineral oil (MO) and synthetic oil.  Some of these popularly used refrigerants are R421A and R407C.  Please consult your user manual or contact an HVAC technician to determine what type of oil is best for your AC unit.

How to Tell if your Air Conditioner Needs Oil

Is your compressor low on oil? It could be quickly harmed if so.

The purpose of oil is to keep all the parts lubricated and also help cool any of the moving parts that are located in the compressor.  There is also an added function for compressor oil – an oily film protects the rubber seals in the lines and at any joints or connections.  In short, the oil seals the entire compressor.

Here are the telltale signs that your compressor may need oil – and whether the damage can be repaired (yes) or the compressor must be replaced (no):

  • Your air conditioner recently started making an odd or strange humming noise (yes).
  • The compressor has a hard time starting or takes longer than normal to start working (yes).
  • The compressor or lines are showing signs of a leak (yes).
  • Smoke or an odd, burning smell is exiting the compressor (probably no).
  • The compressor on your AC unit seizes or freezes up….it stops working (definitely no).

How to Check the Oil Level in your HVAC System

Call a technician and pay them to do it – That’s probably the best way to ensure proper AC or heat pump maintenance.

However, if you enjoy the DIY process, there are a couple of ways you can check to see if you have a low oil level in your air conditioning unit’s compressor.

1). Check the oil level on the compressor’s sight glass that is common on many HVAC systems.   The sight glass will show you the oil level and you can easily tell if you need to have an HVAC technician come out to add oil and possibly more refrigerant.

2). A second way is to hire a professional HVAC technician to come out and do a thorough inspection of your air conditioner. Yes, we know we mentioned it, but we thought it bears repeating. Compressors are expensive – about $1,200 to more than $2,000 to repair according to our AC Compressor Repair Cost Guide, so maybe it makes sense to spend $100-$150 on a pro to make sure you are good to go.

Should I Add Oil to My AC Unit?

Air conditioning units shouldn’t burn oil. But they might leak. If your compressor lubrication/lubricant is low, then it means there has been a leak which has caused it to lose oil.

And yes, oil should be added, but not before the leak is repaired.

Contact a professional HVAC technician to ensure that the leak is fixed and the proper oil is added. After adding AC compressor oil, the technician should check/test to determine that the entire AC system is sealed and functioning properly.   Lack of oil or an oil leak can cause major problems to your HVAC system.

Whenever you recharge your HVAC system with refrigerant, you should also add or replace compressor oil since the old refrigerant will have some of the original oil mixed with it. In short, some will be lost. Complete replacement of the oil, rather than just topping it off, is preferred.

If you are mechanically inclined, you can add the oil yourself by following the manufacturer’s directions in your air conditioning unit’s owner’s manual.

Key Points About Compressor Oil Maintenance

Let’s recap the information here:

1). Your AC needs oil for the compressor to function properly and efficiently.

2). Mineral oil (MO) and synthetic oil are manufactured.

3). The type of oil that your AC unit requires depends on the type of refrigerant that your unit runs on.

4). Oil shouldn’t leak, so if your heat pump or AC is low on oil, the leak should be repaired before oil is added.

5). This is one HVAC repair we think is best left to an air conditioning professional who does this type of work on a regular basis. If you’ve got a bad AC capacitor or need the coil cleaned, those are good DIY projects. This one isn’t, nor is an AC recharge.

You might find more information that will help with AC maintenance and repairs related to the problems you’re having on these pages of Pick HVAC.


After you’ve gone through the complete steps, the next step is the best way to add oil into the compressor of your air conditioner. There are a variety of methods to replace the oil that you will find online in the present, and one of them is the one we suggest you can apply.
However, if this isn’t enough for you, you can always consult an expert to get the job done with no anxiety. It might cost you but it’ll exceed your requirements.