Refrigerant Service Stations
Refrigerant service stations recover, evacuate and recharge automotive air conditioning systems. These machines are dedicated; refrigerants are not to be mixed. A refrigerant identifier is used to insure the refrigerant in the system is the same as the refrigerant in the label. Mixed refrigerants are stored in a gray container with a yellow top.
The recovery process involves retrieving the refrigerant from the system, drying and filtering it, and then storing it in a storage tank located in the cabinet for use in this vehicle or another. After the gauge reads zero, wait 10 minutes or so to see if the gauge increases indicating the system is not completely empty. Repeat the recovery process if necessary.
Evacuating an automotive air conditioning system removes damaging moisture from the system. Moisture enters the system as a vapor and must be heated to its boiling point before it's removed with a vacuum pump. Drawing a closed A/C system into a vacuum lowers the boiling point, so the moisture can be vaporized and drawn out of the system. The system can be leak tested by allowing the system to rest for a specified period of time and monitoring the gauge. If the gauge increases .01 inches of mercury or more, the system should be leak tested.
Charge the system by weight. Most of today’s machines have a database of refrigerant charges by vehicle year, make and model. A passenger car may hold 1.5 pounds of refrigerant while a passenger van with dual units may contain 7 or 8 pounds of refrigerant. Always replace the exact amount of oil lost during recovery. Machines have a collection bottle and manufactures publish lists with the specific amounts that should be added when replacing different components.