Q: How to Replace an Evaporator in a Heater/Air Conditioning Unit?
A: The evaporator is a small radiator-like component mounted in the heater/air conditioning unit under the dash. It removes heat from the passenger compartment. Have the air conditioning system discharged. Disconnect the cable at the negative terminal of the battery. Remove the heater/air conditioning unit from under the dash area. Turn the heater/air conditioning unit upside down and remove the screws that retain the two halves together. Remove the evaporator from the lower housing. Installation is the reverse of the removal procedure. If the evaporator was replaced with a new unit, add 1.5 oz (45 ml) of refrigerant oil (of a type designated as compatible it refrigerant R-134a) to the system. Note: New R-134a-compatible O-rings should be use in each fitting during reassembly. Have the system evacuated, recharged and leak tested by a dealer service department or an air conditioning repair facility.