Evaporator Core: Description and Operation

NOTE:
- Installation of a new suction accumulator/drier is not required when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator/drier.
- The evaporator core is serviced as a core and housing assembly. The evaporator core internal doors, seals and door linkage are included with the housing.

The A/C evaporator core is the plate/fin type with a unique refrigerant flow path.
- A mixture of refrigerant and oil enters the bottom of the A/C evaporator core through the A/C evaporator core inlet tube and is routed so it flows through the partitioned first three plate/fin sections.
- The next four plate/fin sections are partitioned to force the refrigerant to flow toward the other end of tile A/C evaporator core.
- Refrigerant then continues over to the remaining five plate/fin sections and then moves out of the A/C evaporator core through the A/C evaporator core outlet tube.
- This S-pass flow pattern accelerates the flow of refrigerant and oil through the A/C evaporator core.

A/C Evaporator Core Orifice
NOTE: A new A/C evaporator core orifice should be installed whenever a new A/C compressor is installed.

The A/C evaporator core orifice has the following characteristics:
- Is color-coded orange.
- Has an orifice diameter of 1.45 mm (0.057 inch).
- Is located in the aft condenser to evaporator tube.
- Has filter screens located on the inlet and outlet ends of the tube body.
- The inlet filter screen acts as a strainer for the liquid refrigerant flowing through the A/C evaporator core orifice.
- O-ring seals on the A/C evaporator core orifice prevent the high-pressure liquid refrigerant from by-passing the A/C evaporator core orifice.
- Adjustment or repair cannot be made to the A/C evaporator core orifice assembly. It must be installed as a unit. This requires installation of the condenser to evaporator tube or installation of the Evaporator Core Orifice Replacement Kit.