Discharging A/C System

R-134a systems require the use of special service equipment designed specifically to be compatible with them. R-12 service equipment cannot be used on R-134a systems. Recovery and recycling stations must also be compatible with the type of refrigerant in use; a station will be contaminated if it is used in conjunction with an incompatible refrigerant.

Refrigerant recovery and recycling stations allow the retention and reuse of refrigerant after contaminants and moisture have been removed. When using such a station, follow the manufacturer's operating instructions, noting the following:

1. Use extreme caution and observe all safety and service precautions related to the use of refrigerants.
2. Connect refrigerant recycling station hose(s) to vehicle A/C service port(s) and recovery station inlet fitting. Use hoses equipped with shutoff devices or check valves located within 12 inches of hose ends to minimize introduction of air into recycling station and to minimize amount of refrigerant released when hose ends are disconnected.
3. Turn recycling station on to begin recovery process. Allow station to pump refrigerant from A/C system until station pressure gauge indicates vacuum.
4. After vehicle A/C system has been evacuated, close station inlet valve, if equipped.
5. Turn station off. Some stations may be shut off automatically by a low pressure switch.
6. Allow vehicle A/C system to remain closed for approximately two minutes. Observe vacuum level indicated on gauge. If pressure does not rise, disconnect recycling station hose(s).
7. If system pressure rises, repeat recovery steps until vacuum level remains stable for two minutes.
8. Service A/C system as necessary, then evacuate and recharge A/C system.