How to Add Refrigerant Oil to Car Air Conditioning?

[DelJourney]

There are two methods for adding refrigerant oil to car air conditioning: the direct pouring method and the vacuum suction method. Direct Pouring Method: Pour the refrigerant oil into a clean measuring bottle and then directly pour it into the compressor's plug port. This method is suitable when replacing the evaporator, condenser, and receiver-drier. Vacuum Suction Method: 1. Evacuate the system to 100kPa; 2. Prepare a measuring cup with graduations and fill it with slightly more refrigerant oil than the required amount; 3. Close the high-pressure manual valve and the auxiliary valve, disconnect one end of the high-pressure hose from the manifold gauge set, and insert it into the measuring cup; 4. Open the auxiliary valve, and the oil will be sucked into the system from the measuring cup; 5. When the oil level reaches the specified graduation, immediately close the auxiliary valve.

[Fred]

Last time I added refrigerant oil to my car myself, it was quite a hassle. At first, I didn't know the proper method and ended up making a mess everywhere. Actually, adding refrigerant oil requires first recovering all the refrigerant completely; otherwise, the oil won't go in. The specific steps are to remove the oil drain bolt at the bottom of the compressor and drain out all the old oil. The new oil must be precisely measured using a dedicated measuring cup, then slowly poured into the compressor's oil filler port. Remember to replace the gasket before tightening the bolt, or it might leak. During the operation, it's essential to keep the environment clean—not even a speck of dust should fall in. Finally, you need to vacuum the system and then recharge it with refrigerant to test the pressure. I suggest that those who aren't very handy avoid doing this themselves and just go to a professional shop—it's much easier since they have all the right tools and more experience.

[ErinLee]

Adding refrigerant oil to a car's AC system requires professional equipment. First, the refrigerant in the system must be completely evacuated, then the compressor is disassembled to drain the old oil. Adding new oil must follow the precise amount specified in the manual—even a slight excess can damage the pipelines. The type of refrigerant oil is also crucial; some vehicles use PAG oil, while others require POE oil. Using the wrong type can potentially ruin the entire system. I once had to replace a compressor because I used the wrong oil type. Every connection must be meticulously sealed during the process, as air and moisture contamination are major concerns. The vacuuming step is especially critical and typically takes at least 30 minutes. Honestly, this job tests both skill and patience—without professional equipment, it's nearly impossible. I recommend having it handled by an authorized service center.

[VonElizabeth]

Adding refrigerant oil is actually a technical task. If the air conditioning in a new car isn't cooling properly after a few years, it may be necessary to check the refrigerant oil level. Under normal circumstances, refrigerant oil and refrigerant are sealed in a closed loop, so it generally doesn't need to be added separately. Refrigerant oil is only replenished when the air conditioning lines have been repaired or the compressor has been replaced. The specific amount to add depends on the compressor model, typically ranging from 30 to 60 milliliters. During the operation, the old oil must be drained, and the oil pan cleaned before refilling. The entire process requires keeping the system dry, which necessitates professional vacuum equipment. I believe ordinary car owners don't need to learn this; it's safest to have it handled by a repair shop.