GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2004 🢒 Silhouette Ext. 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Air Conditioning Evaporator Core Replacement

Removal Procedure
  1. Remove the HVAC module assembly. Refer to HVAC Module Assembly Replacement .
  2. Disconnect the evaporator temperature sensor connector from the air inlet housing.

    3. Object Number: 825400 Size: SH
  3. Remove the air inlet housing screws.
  4. Remove the air inlet housing from the HVAC module.

    5. Object Number: 825399 Size: SH
  5. Remove the right side HVAC module assembly mounting bracket screws.
  6. Remove the right side HVAC module assembly mounting bracket.

    7. Important: The HVAC module assembly upper retaining screw is located under the right HVAC module assembly mounting bracket.

  7. Remove the upper HVAC module retaining screw.

    8. Object Number: 825392 Size: SH
  8. Remove the HVAC module assembly to dash panel sound barrier seal.

    9. Object Number: 825398 Size: SH
  9. Remove the screws retaining the heater outlet duct.
  10. Remove the heater outlet duct.

    11. Object Number: 825396 Size: SH
  11. Remove the heater core cover screws.
  12. Remove the heater core cover.

    13. Object Number: 825397 Size: SH
  13. Remove the heater core pipe retaining screw.
  14. Remove the heater core.

    15. Important: The lower HVAC module assembly retaining screw is located under the heater core.

  15. Remove the lower HVAC module assembly retaining screw.

    16. Object Number: 825389 Size: SH
  16. Remove the lower HVAC module assembly retaining screws.
  17. Separate the upper and lower HVAC module halves.

    18. Object Number: 295362 Size: SH
  18. Remove the evaporator core from the upper HVAC module case half.

    19. Object Number: 825391 Size: SH
  19. Remove the evaporator temperature sensor.

    20. Object Number: 791147 Size: SH
  20. Remove the TXV mounting screws.
  21. Remove the TXV from the evaporator core.
  22. Remove and discard the sealing washers.

Installation Procedure
  1. If replacing the evaporator core add the specified amount of PAG oil directly to the evaporator core. Refer to Refrigerant System Capacities .
  2. Install the new sealing washers onto the evaporator line. Refer to Sealing Washer Replacement .

    3. Object Number: 791147 Size: SH
  3. Install the TXV to the evaporator core.

    4. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  4. Install the TXV mounting screws.

    5. Tighten
    Tighten the screws to 3.2 N·m (28 lb in).


    Object Number: 825391 Size: SH

    Important: The evaporator temperature sensor must be located in the same position on the new evaporator core.

  5. The evaporator temperature sensor should be approximately 3.5 cm (1.4 in) from the side and 5.0 cm (2.0 in) from the bottom corner of the evaporator core.
  6. Install the evaporator temperature sensor.

    7. Object Number: 295362 Size: SH

    Important: Align the evaporator temperature sensor wires with the opening in the upper HVAC module case. Improper alignment will pinch and/or cut the sensor wires.

  7. Install the evaporator core into the upper HVAC module case half.

    8. Object Number: 825389 Size: SH
  8. Align and install the upper module case to the lower module case.
  9. Install the lower HVAC module assembly retaining screws.

    10. Tighten
    Tighten the screws to 0.9 N·m (8 lb in).

  10. Install the lower HVAC module assembly retaining screw.

    11. Tighten
    Tighten the screw to 0.9 N·m (8 lb in).


    Object Number: 825397 Size: SH
  11. Install the heater core.
  12. Install the heater core pipe retaining screw.

    13. Tighten
    Tighten the screw to 0.9 N·m (8 lb in).


    Object Number: 825396 Size: SH
  13. Install the heater core cover.
  14. Install the heater core cover screws.

    15. Tighten
    Tighten the screws to 0.9 N·m (8 lb in).


    Object Number: 825398 Size: SH
  15. Install the heater outlet duct.
  16. Install the heater outlet duct screws.

    17. Tighten
    Tighten the screws to 0.9 N·m (8 lb in).


    Object Number: 825392 Size: SH
  17. Install the HVAC module assembly to dash panel sound barrier seal.
  18. Install the HVAC module upper retaining screw.

    19. Tighten
    Tighten the screw to 0.9 N·m (8 lb in).


    Object Number: 825399 Size: SH
  19. Install the right side HVAC module assembly mounting bracket.
  20. Install the right side HVAC module assembly mounting bracket screws.

    21. Tighten
    Tighten the screws to 1.8 N·m (16 lb in).


    Object Number: 825400 Size: SH
  21. Install the air inlet housing to the HVAC module.
  22. Install the air inlet retaining screws.

    23. Tighten
    Tighten the screws to 0.9 N·m (8 lb in).

  23. Connect the evaporator temperature sensor connector to the air inlet housing.
  24. Install the HVAC module assembly. Refer to HVAC Module Assembly Replacement .