Diesel Data: Automotive Repair

Expansion Block/Orifice Tube: Description and Operation

A/C EVAPORATOR CORE ORIFICE

The A/C evaporator core orifice has the following characteristics:
- It is located in the rear condenser to evaporator tube and can be removed through an access fitting.
- It 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 bypassing the A/C evaporator core orifice.
- Adjustment or repair cannot be made to the A/C evaporator core orifice assembly. It must be serviced as a unit.