GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Corvette 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Heater Core Replacement

Removal Procedure

    Object Number: 295347 Size: SH
  1. Remove the HVAC module. Refer to HVAC Module Assembly Replacement .
  2. Remove the heater core outlet cover screws.
  3. Remove the heater core outlet cover.

    4. Object Number: 295349 Size: SH
  4. Remove the heater core cover screws.
  5. Remove the heater core cover.

    6. Object Number: 143978 Size: SH
  6. Remove and discard the seals (1,2,3) from the heater core cover.

    7. Object Number: 296242 Size: SH
  7. Remove and discard the heater core outer seal (5) from the heater core.

    8. Object Number: 295351 Size: SH
  8. Remove the heater core retaining clamp screw (1).
  9. Remove the heater core retaining clamp.
  10. Remove the heater core pipe retainer clamp screw (2).

    11. Object Number: 295353 Size: SH
  11. Remove the heater core from the HVAC module case - lower.

    12. Object Number: 143987 Size: SH
  12. Remove and discard the heater core lower seal (4) from the HVAC module case - lower.

    13. Object Number: 143992 Size: SH
  13. Remove and discard the heater core center seal (3) from the HVAC module case - lower.

    14. Object Number: 143985 Size: SH
  14. Remove and discard the heater core upper seal (2) from the HVAC module case - lower.

    15. Object Number: 143990 Size: SH
  15. Remove and discard the heater core side seals (1) from the HVAC module case - lower.

    16. Object Number: 295355 Size: SH
  16. Remove the heater core pipe retainer clamp from the heater core pipes.

    17. Using a flat bladed tool, release the retaining tab and open the clamp.

Installation Procedure

    Object Number: 295355 Size: SH
  1. Install the heater core pipe retainer clamp to the heater core pipes.

    2. Align the depression in the clamp to the ridge on one of the heater core pipes, then close the clamp to secure.


    Object Number: 143990 Size: SH
  2. Install new heater core side seals (1) to the HVAC module case - lower.

    3. Object Number: 143985 Size: SH
  3. Install a new heater core upper seal (2) to the HVAC module case - lower.

    4. Object Number: 143992 Size: SH
  4. Install a new heater core center seal (3) to the HVAC module case - lower.

    5. Object Number: 143987 Size: SH
  5. Install a new heater core lower seal (4) to the HVAC module case - lower.

    6. Object Number: 295353 Size: SH
  6. Install the heater core to the HVAC module case - lower.

    7. Object Number: 295351 Size: SH

    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.

  7. Install the heater core pipe retainer clamp screw (2).

    8. Tighten
    Tighten the screw to 1.6 N·m (14 lb in).

  8. Install the heater core retaining clamp.
  9. Install the heater core retaining clamp screw (1).

    10. Tighten
    Tighten the screw to 1.6 N·m (14 lb in).


    Object Number: 296242 Size: SH
  10. Install a new heater core outer seal (5) to the heater core.

    11. Object Number: 143978 Size: SH
  11. Install new cavity seals (1,2,3) to the heater core cover.

    12. Object Number: 295349 Size: SH
  12. Install the heater core cover.
  13. Install the heater core cover screws.

    14. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 295347 Size: SH
  14. Install the heater core outlet cover.
  15. Install the heater core outlet cover screws.

    16. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).

  16. Install the HVAC module. Refer to HVAC Module Assembly Replacement .