GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2001 🢒 Silhouette Ext. 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Auxiliary Heater Core Replacement

Removal Procedure
  1. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

    3. Object Number: 400657 Size: SH
  3. Disconnect the auxiliary heater hoses from the auxiliary heater core pipes.
  4. Lower the vehicle.
  5. Remove the left rear quarter trim panel. Refer to Rear Quarter Lower Trim Panel Replacement in Interior Trim.

    6. Object Number: 691719 Size: SH
  6. Remove the auxiliary heater pipe clamp screw.
  7. Remove the auxiliary heater pipe clamp.
  8. Disconnect the auxiliary inlet heater hose clamp.

    9. Slide the hose clamp up onto the heater core pipe.

  9. Remove the auxiliary inlet heater hose from the heater core.

    10. Slide the heater hose and pipe extension downward.

  10. Disconnect the auxiliary outlet heater hose clamp.

    11. Slide the hose clamp up onto the heater core pipe.

  11. Remove the auxiliary outlet heater hose from the heater core.

    12. Slide the heater hose and pipe extension downward.


    Object Number: 691755 Size: SH
  12. Remove the auxiliary heater core mounting screws.
  13. Remove the auxiliary heater core from the HVAC module assembly.

    14. Object Number: 718090 Size: SH
  14. Remove the heater core mounting bracket from the auxiliary heater core.

Installation Procedure

    Object Number: 718090 Size: SH
  1. Install the heater core mounting bracket to the auxiliary heater core.

    2. Object Number: 691755 Size: SH
  2. Install the auxiliary heater core to the HVAC module assembly.

    3. 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.

  3. Install the auxiliary heater core mounting screws.

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


    Object Number: 691719 Size: SH
  4. Install the hose clamps to the auxiliary heater core pipes.
  5. Install the outlet heater hose to the auxiliary heater core.
  6. Install the inlet heater hose to the auxiliary heater core.

    7. Important: Align the inlet and outlet pipes to allow for the heater pipe clamp installation.

  7. Install the auxiliary heater pipe clamp.
  8. Install the auxiliary heater pipe clamp screw.

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

  9. Connect the auxiliary outlet heater hose clamp.
  10. Connect the auxiliary inlet heater hose clamp.
  11. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  12. Connect the auxiliary heater hoses to the heater core pipes.
  13. Lower the vehicle.
  14. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  15. Install the left rear quarter trim panel. Refer to Rear Quarter Lower Trim Panel Replacement in Interior Trim.