Refrigerant Filter: Description and Operation

The filter-drier is located in the engine compartment near the dash panel on the passenger side of the vehicle. The filter-drier incorporates a sight glass for visual diagnosis of the refrigerant system

High-pressure liquid refrigerant from the condenser flows into the filter-drier. A drying agent, called a desiccant, is used to remove any traces of moisture from the refrigerant system. The filter-drier also performs a filtering action to prevent foreign material in the refrigerant from contaminating the expansion valve. In addition, during periods of high demand air conditioner operation, the filter-drier acts as a reservoir to store surplus refrigerant.

The A/C refrigerant must be removed from the system before removing the filter/drier using a refrigerant recovery machine. Replace the filter/drier if an A/C system is left open for an extended period of time.

The filter-drier cannot be repaired and, if faulty, must be replaced.