Expansion Block/Orifice Tube: Description and Operation

NOTE: The A/C evaporator core orifice should be replaced whenever the A/C compressor is replaced.

The A/C evaporator core orifice is a restriction between the high and low-pressure liquid refrigerant. The A/C evaporator core orifice meters the flow of liquid refrigerant into the A/C evaporator core.

The A/C evaporator core orifice has the following characteristics:
^ Color-coded green.
^ Diameter of 1.32 mm (0.052 in).
^ Located in the rear condenser to evaporator tube.
^ Filter screens positioned on the orifice inlet and outlet ports.
^ O-rings on the orifice body prevent the liquid refrigerant from bypassing the A/C evaporator core orifice.