A car’s air conditioning system requires a specific amount of oil to function, just like the engine. You should have a clear idea of how much PAG oil to add to the air conditioning system to protect it from unexpected failure.
Which AC components require an oil refill?
The compressor is the component of the air conditioning unit that needs adequate oil to function properly. The compressor is responsible for compressing the refrigerant and circulating it through the rest of the system. When the refrigerant passes through the compressor, it also carries oil with it, which lubricates the compressor’s moving parts. Normally, it is not necessary to add oil to your vehicle’s existing air conditioning system unless you have changed the compressor or there is a leak, allowing oil to escape from the system.
A compressor requires a sufficient amount of oil for lubrication. It has cylinders to compress the refrigerant gases, which creates heat and friction. The oil present in the system controls this heat and reduces friction by making the parts more slippery.
The other components of the air conditioning system, such as the condenser, evaporator, and expansion valve, do not require lubrication and therefore do not need an oil top-up.
However, it is important to note that if any of these components are replaced due to a malfunction or leak, they must be drained of any remaining refrigerant and oil, and the correct amount of oil must be added to the system when recharging it. This ensures that the system has the appropriate amount of oil for proper lubrication and to avoid damaging the compressor and other components.
If there is a leak in the system, repair it first before adding oil. Otherwise, the system will soon need more oil and could lead to the failure of some parts.
What is PAG oil?
PAG oil, or Polyalkylene Glycol, is specially created for automotive air conditioning compressors. The fully synthetic hygroscopic oil is a compressor lubricant for air conditioning units that use R-134a refrigerant.
In addition to knowing how much PAG oil to add to the air conditioning system, you must also use an oil with the correct viscosity. Each type of PAG oil has a number such as PAG150 or PAG VC-46. This number refers to the viscosity of the PAG, similar to how a number like 10W30 indicates the viscosity of regular engine oil.
PAG oil is highly hygroscopic, meaning it absorbs moisture from the air. Therefore, it is important to keep it sealed in an airtight container until ready for use. It is also important to use the appropriate type of PAG oil for a particular air conditioning system, as different systems may require different viscosities or additive packages.
PAG oil is often used in automotive air conditioning systems due to its high lubricating power and stability at high temperatures. It is also non-toxic and has a low environmental impact, making it a good choice for use in automotive applications.
You should consult the owner’s manual for the correct viscosity of PAG oil for the air conditioning compressor.
Learn how to add PAG oil to the air conditioning system in this video:
How much PAG oil should be added to the air conditioning system
Like engine oil, PAG oil serves as a lubricant for the compressor and circulates the refrigerant throughout the air conditioning system. However, the exact amount of PAG oil to add to the air conditioning system will depend on several factors: the air conditioner’s design, its capacity, and the type of compressor.
Additionally, the air conditioning system’s compressor will likely have specifications regarding the amount of oil to add. You should consult the owner’s manual before adding more oil.
The air conditioning system of most modern vehicles needs a total of 4 ounces (120 ml) of oil. Therefore, it is wise to consult the manual to be sure of the exact amount and avoid overfilling or underfilling the system. A low oil level can lead to compressor failure, and overfilling will also harm cooling performance.
So, how much PAG oil to add when recharging the AC? Here is the amount of PAG oil that different AC components need for their proper functioning:
- Compressor = 1.4 ounces
- Evaporator = 1.5 ounces
- Condenser = 1 ounce
- Accumulator = 1 ounce
- Hoses = 1 ounce
To ensure that the appropriate amount of PAG oil is added to the air conditioning system, you should refer to the vehicle’s manual and seek assistance from a trusted automotive mechanic.
It is recommended to flush the entire system before adding oil or refrigerant. When replacing a part, such as a compressor or accumulator, you should always add the oil that was lost during the replacement.
However, the total amount of oil added should never exceed the system’s oil capacity. So, when calculating how much PAG oil to add to the air conditioning system, remember to keep the total amount below 4 ounces or whatever your car’s air conditioning system capacity is.