How to add oil to air conditioning compressor

You probably take for granted how your air conditioning system keeps the air cool during a hot day. But, things change once your air conditioner starts to blow hot air and you are left dripping with sweat. Your air conditioning unit works are a simple concept, but it needs some unique equipment pieces to work and function properly. Learning how to add oil to the air conditioning compressor is one of the things you need to ensure that your unit keeps you cool whenever you need and want it to.

The majority of refrigeration systems work based on the simple principle that the temperature of the gas drops once it expands or what is scientifically known as the Joule-Thompson effect. You might have already witnessed this in action if you have ever experienced using a carbon dioxide fire extinguisher. Once the gas gets released, the leftover carbon dioxide in the extinguisher expands and causes a cooling off in the fire extinguisher.

The exact opposite is true as well. The gas heats up if it is compressed. It is a similar principle that makes a diesel engine work, and you can also see it if you use a bicycle pump for inflating a tire. Take note of how the hose and the pump become partially hot because of air compression.

Your air conditioning compressor is the one that compresses your air conditioning’s refrigerant where it heats up as well. It is then cooled back to the atmospheric temperature within the condenser. The expansion of the atmospheric refrigerant is allowed through the orifice tube or expansion valve.

This expansion will make the refrigerant cool lower than the atmospheric temperature in which it will travel to the evaporator. Cabin air will pass over the evaporator that causes the air to cool with the refrigerant going back to atmospheric temperature. This will go back to the compressor to begin the process all over again from there.

The best way to lengthen the life span of your AC compressor is to make sure that you add enough oil whenever you add refrigerant to the system.

Steps for Adding Oil to Air Conditioning Compressor

A recovery machine must be used to evacuate the air conditioning system if you want to add oil to the air conditioning compressor. This is because releasing refrigerants into the atmosphere is considered illegal. To do it properly, all air conditioning systems have a particular amount of refrigerant oil that is based on the length of the hoses for the air conditioning system.

Refrigerant oil gets suspended within the Freon and excessive oil clogs the components and may negatively affect the unit’s operation. Once a leak within the system is located and fixed, like loose-fitting, it is safe to introduce a small quantity of oil to the system even while the engine runs without causing any danger to the unit.

  1. A reclaimer should be hooked to the low and high side valves on your air conditioning unit. Its high side is that tiny diameter line while the low side is the big diameter line. You can turn on the machine power and have the charging tank opened.
  2. Open the red and blue valves for the high and low side respectively located in front of the reclaimer. You should push that button labeled reclaim. Allow it to run in that mode until the two gauges show 0. Turn off the valves to both low and high side valves and ensure that the two gauges read 0.
  3. Remove the low and high lines from the AC unit on the engine. The electrical connector should be removed from the AC compressor. The air conditioning drive belt should also be removed.  You also need to remove the AC manifold lines connected to the air compressor. You can now remove the AC compressor.
  4. All the oil in the air conditioning compressor should be emptied through holding down the open end while manually rotating the clutch in the normal rotation direction. You can learn about the information on the right amount of oil from the air conditioning sticker or from the maintenance manual. The following steps should be carried out in an almost sterile way.  It means that no foreign sediment should get inside the compressor as it can end up harming the system’s operation.
  5. The oil should be poured very slowly to the low side or intake port of the compressor. It is the point of entry of the large line. As you pour the refrigerant oil in, the clutch and hub should be rotated slowly to allow the oil to get inside the compressor. If the instruction states that the compressor can take 6 oz. of oil, all the 6 oz.  should be used but make sure that it is completely refrigerant oil since nothing else is going to work. After you are done with this, lay down the compressor on the hub for about 10 minutes to allow the oil to seep to the front seals and lubricate them to prevent any leaks during startup.
  6. The compressor should now be installed and the hub must be spun by hand 10 times. The drive belt should also be installed. See to it that the manifold attaching the lines to the rear of the compressor has good and totally clean o-rings. The manifold should be attached the bolt must be properly tightened.
  7. The electrical connector should be installed on the compressor and the low and high side hoses must now be reattached from the reclaimer. You need to open the reclaimer’s valves then hit on the button labeled “vacuum.” Once you are asked by the reclaimer for how long, just enter 30 minutes then hit on “start” button. 

Both valves should be closed after shutting off the vacuum pump. Monitor the gauges for any leaks. The gauges must show around 30 inches of mercury. A drop in the gauges indicates a leak. Open the valves on the high and low sides then hit the charge button. Allow the lines to be charged. Once the panel states that the charge is already complete, shut off both of the reclaimer’s valves then remove the lines from your AC unit before installing the caps on the valves.

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