How much refrigerant oil should I add to the A/C system when recharging?
As outlined above, there may not be a requirement to add oil to the A/C system every time it’s recharged. However, if the system requires oil, you should only be adding the amount of oil that’s been lost. With leaks or ‘normal’ loss of refrigerant oil through the a/c compressor shaft seals it may be difficult to determine exactly how much to add. Therefore, you should follow the general ‘rules’. Adding 1-2 ounces for loss through small leaks or through the compressor shaft seal is acceptable. When replacing components, there are additional guidelines that should be followed. They are; A/C Condenser – 1 oz.; Accumulator or receiver drier – 1 oz.; Evaporator – 3 oz.; Compressor – Generally, the amount removed plus one ounce (1oz.). For more detailed refrigerant oil specifications, follow the service manual for your specific application.
