GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1997 🢒 Corvette 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Heater Core

Removal Procedure

    Object Number: 143978 Size: SH
  1. Disconnect the negative battery cable. Refer to

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

    in General Information.
  2. Discharge the A/C system. Refer to Refrigerant Recovery and Recharging

    3. .

  3. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  4. Remove the Heater/Evaporator Module. Refer to Heater/Evaporator Module Assembly .
  5. Remove the heater core cover.
  6. Remove and discard the cavity (1), whistle (2), and permagum (3) seals.

    7. Object Number: 143994 Size: SH
  7. On vehicles equipped with the CJ2 A/C system remove and discard the outer heater core seal (3).
  8. Remove the heater core mounting clip screws (1).
  9. Remove the heater core pipe screw (2).
  10. Remove the heater core.

    11. Object Number: 143987 Size: SH
  11. Remove the lower heater core seal from the heater/evaporator module and discard.

    12. Object Number: 143992 Size: SH
  12. On vehicles equipped with the CJ2 A/C system remove the center heater core seals from the heater/evaporator module and discard.

    13. Object Number: 143985 Size: SH
  13. Remove the upper heater core seal from the heater/evaporator module and discard.

    14. Object Number: 143990 Size: SH
  14. Remove the side heater core seals from the heater/evaporator module and discard.

Installation Procedure

    Object Number: 143990 Size: SH
  1. Install two new side heater core seals on the heater/evaporator module.

    2. Object Number: 143985 Size: SH
  2. Install a new upper heater core seal on the heater/evaporator module.

    3. Object Number: 143992 Size: SH
  3. On vehicles equipped with the CJ2 A/C system install a new center heater core seal on the heater/evaporator module.

    4. Object Number: 143987 Size: SH
  4. Install a new lower heater core seal on the heater/evaporator module.

    5. Object Number: 143994 Size: SH
  5. Install the heater core into the heater/evaporator module.
  6. On vehicles equipped with the CJ2 A/C system, install a new outer heater core seal (3).
  7. Install the heater core pipe screw (2).
  8. Install the heater core mounting clip screw (3).

    9. Tighten

        • Tighten the heater core pipe screw to 1.6 N·m (14 lb in).
        • Tighten the heater core mounting clip screw to 1.6 N·m (14 lb in).

    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.


    Object Number: 143978 Size: SH
  9. Install new cavity (1), whistle (2), and permagum (3) seals on the heater core cover.
  10. Install the heater core cover.

    11. Tighten
    Tighten the heater core cover screws to 1.6 N·m (14 lb in).

  11. Install the heater/evaporator module into the vehicle. Refer to Heater/Evaporator Module Assembly .
  12. Connect the negative battery cable. Refer to

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

    .
  13. Fill the cooling system. Refer to Cooling System Draining and Filling

    14. in Engine Cooling.

  14. Evacuate and recharge the A/C system. Refer to Evacuation and Air Conditioning (A/C) Charging Using ACR4 .