Ac compressor

Hi,

If it's the original RV type compressor the shop manual covers the procedure. The system must have all the refrigerant out of it. There is a small plug at the base of the compressor on the left side as you face the compressor. You remove this plug and use a small dipstick made up from the dimensions in the shop manual.

If your dipstick measurements show you need to add oil the next question is what type of oil is in the system. If the system has its original R-12 refrigerant the answer is easy- 525 A/C mineral oil. If the system has been converted to R134A there may be one of two oil types PAG or Polyester. They are not interchangeable and can not be mixed so you need to know what is in the system. Converted systems are supposed to be labeled as to oil type but frequently are not and that's when the real fun starts.

If its a Sanden type compressor, you have to remove the compressor, dump out the oil, measure and refill to specifications for the compressor type.