GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1998 🢒 Cutlass 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Heater Core Replacement

Removal Procedure

    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.

  1. Disconnect the negative battery cable.
  2. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  3. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

    4. Object Number: 367436 Size: SH
  4. Drain the tube from the heater case (4).
  5. Remove the heater hoses from the heater core (1). Refer to Heater Hoses Replacement .
  6. Lower the vehicle.
  7. Remove the console and the instrument panel. Refer to Console Replacement in Instrument Panel, Gauges, and Console.
  8. Remove the floor air outlet duct. Refer to Floor Air Outlet Replacement .
  9. Remove the heater core cover (4).
  10. Remove the heater core mounting clamps (2).
  11. Remove the heater core (1).

Installation Procedure

    Object Number: 367436 Size: SH
  1. Install the heater core (1).

    2. 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.

  2. Install the heater core mounting clamps (2).

    3. Tighten
    Tighten the screws to 1 N·m (9 lb in).

  3. Install the heater core cover.

    4. Tighten
    Tighten the screws to 1 N·m (9 lb in).

  4. Install the floor air outlet.

    5. Tighten
    Tighten the screws to 1 N·m (9 lb in).

  5. Install the console and the instrument panel. Refer to Console Replacement in Instrument Panel, Gauges, and Console.
  6. Install the steering column opening filler.
  7. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  8. Install the heater hoses to the heater core (1). Refer to Heater Hoses Replacement .
  9. Lower the vehicle.
  10. Connect the negative battery cable.

    11. Tighten
    Tighten the bolt to 16 N·m (12 lb ft).

  11. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  12. Inspect the cooling system for leaks. Refer to Cooling System Leak Testing in Engine Cooling.