Air conditioning refrigerant commonly known as “Freon” should be checked for proper pressures and level of refrigerant oil periodically. Low Freon and refrigerant oil levels can cause premature wear on air compressors, and decrease overall performance of the a/c system. Although the a/c system is a sealed unit, it is not uncommon to have to add small amounts of “Freon” periodically due to small leaks and seepage. Freon is a gas that is under high pressure and should only be service by a trained professional.