Evaporator Core: Service and Repair

Remove or Disconnect

1. Recover refrigerant.
2. Right-hand instrument panel sound insulator panel.
3. Heater hoses at heater core.
4. Instrument panel compartment.
5. Heater core.
6. Temperature control cable at temperature valve case.
7. Bolts/screws located in engine compartment from temperature valve case.
8. Temperature valve case.
^ Slide case downward to disengage upper case clip.
^ Remove from under the instrument panel.

Important
^ Remove perforated section of heater and air conditioning evaporator module as one piece (it will be reused).
^ Water can leak onto carpeting when doing this procedure. It is recommended that a mat be placed on passenger side floor.

9. Using a small hand saw1 remove perforated section of heater and air conditioning evaporator module.

Important
^ This piece of material is required to keep condensate from draining inside vehicle.

10. Bolts/screws retaining air conditioning evaporator.
11. Air conditioning evaporator from heater and air conditioning module.
^ Slide evaporator to the left, then pull out through the opening enlarged in step 11.

Install or Connect

1. Transfer condensate screen to new evaporator.
2. Install new evaporator core gasket in same position as original with appropriate adhesive.
3. Air conditioning evaporator to heater and air conditioning module.
^ Insert evaporator into module through the opening enlarged during removal, slide to the right until fully seated.
4. Bolts/screws to air conditioning evaporator.
5. Apply sealer GM P/N 3012078 (do not use epoxy glue) between evaporator and evaporator upper and lower case just behind thermostatic expansion valve to prevent air entry from the engine compartment into the passenger compartment.
6. Position perforated section of heater and air conditioning evaporator module and use epoxy glue to adhere it to module. After epoxy dries, use thumb to grade sealant on inside and outside to ensure water4ight seal.
7. Temperature valve case.
^ Install from under instrument panel.
^ Slide case upward into position until upper clip engages.
^ Engage snap on left edge of temperature valve case to distributor case.
8. Bolts/screws to temperature valve case.

Tighten
^ Bolts/screws evenly to compress flange seal.

9. Temperature control cable at temperature valve case.
10. Heater core.
11. Instrument panel compartment.
12. Heater hoses to heater core.
13. Right-hand instrument panel sound insulator panel.
14. Fill radiator and bleed cooling system.
15. Refrigerant oil into evaporator, if necessary.
16. Charge A/C system.
^ If installing new evaporator, add 89 ml (3 fluid ounces) of polyalkylene glycol (PAG) synthetic refrigerant oil, GM P/N 12345923.
17. Leak-test fittings.