Adding oil to an air conditioning compressor must be done with the air conditioning system evacuated by a recovery machine, since it is illegal to release refrigerant into the atmosphere. To be done correctly, every air conditioning system has a specific amount of refrigerant oil determined by the length of hoses for the system. The refrigerant oil is suspended in the Freon and too much oil will clog the components and be detrimental to its operation. If a leak in the system has been located and repaired, such as a loose fitting, a small amount of oil can be introduced into the system with the engine running without harm to the unit.
Hook the reclaimer to the high and low side valves on the air conditioning unit. The high side is the small diameter line and the low side is the large diameter line. Turn the machine power on and open the charging tank.