GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Catera 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Heater Core Replacement

Removal Procedure
  1. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

    2. Object Number: 309505 Size: SH
  2. Disconnect the heater hoses from the heater core pipes:
    3. • Raise the air inlet screen on the passenger side and open the access door near the pollen filter.
    • Squeeze the tabs on the locking collar and pull back on the sleeve to unlock.
    • Carefully pull back the tabs to remove the disconnects.
    • Discard the green assembly markers (1) if attached.
  3. Remove the IP carrier. Refer to Instrument Panel Carrier Replacement in Instrument Panel, Gages and Console.

    4. Object Number: 782115 Size: SH
  4. Remove the SIR mounting bracket bolts.
  5. Remove the SIR mounting bracket.

    6. Object Number: 153281 Size: SH
  6. Remove the IP support bracket bolts.
  7. Remove the IP support bracket.

    8. Object Number: 153293 Size: SH
  8. Remove the blower motor housing screws.
  9. Remove the blower motor housing with the motor.

    10. Object Number: 153279 Size: SH
  10. Remove the heater core pipe bracket screw.
  11. Remove the heater core pipe bracket.

    12. Object Number: 153280 Size: SH
  12. Remove the heater core inlet and outlet pipe retaining bracket screw.
  13. Remove the heater core inlet and outlet pipes.

    14. Object Number: 153282 Size: SH
  14. Remove the heater core retaining screw.
  15. Remove the heater core with the rubber seal:
    16. • Protect the surrounding interior trim and carpeting from coolant spills.
    • Plug the heater core ports.
    • Remove the heater core (2).
    • Remove the rubber seal (1) from the cavity.

Installation Procedure

    Object Number: 153282 Size: SH
  1. Install the rubber seal (1) into the heater core cavity.
  2. Install the heater core (2).

    3. Use caution to avoid damage to the fins.

    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 heater core retaining screw.

    4. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).


    Object Number: 153280 Size: SH
  4. Install the heater core inlet and outlet pipes:
    5. • Use new O-rings.
    • Lightly lubricate the O-rings with coolant.
  5. Install the heater core inlet and outlet pipe retaining bracket screw.

    6. Tighten
    Tighten the screw to 5 N·m (44 lb in).


    Object Number: 153279 Size: SH
  6. Install the heater core pipe bracket.
  7. Install the heater core pipe bracket screw.

    8. Tighten
    Tighten the screw to 1.5 N·m (13 lb in).


    Object Number: 153293 Size: SH
  8. Install the blower motor housing with the motor.
  9. Install the blower motor housing screws.

    10. Tighten
    Tighten the screws to 4 N·m (35 lb in).


    Object Number: 153281 Size: SH
  10. Install the IP support bracket.
  11. Install the IP support bracket bolts.

    12. Tighten
    Tighten the bolts to 22 N·m (16 lb ft).


    Object Number: 782115 Size: SH
  12. Install the SIR mounting bracket.
  13. Install the SIR mounting bracket bolts.

    14. Tighten
    Tighten the bolts to 16 N·m (12 lb ft).

  14. Install the IP carrier. Refer to Instrument Panel Carrier Replacement in Instrument Panel, Gages and Console.

    15. Object Number: 309508 Size: SH
  15. Install the heater hose quick connects to the heater core pipe connections:
    16. • Discard green assembly marker (1) if not attached to the quick connect.
    • Inspect that the quick connects are fully seated.
    • Squeeze the locking tabs (2) and push the retaining sleeve (3) into the locked position.
    • Close the access door near the pollen filter and lower the air inlet screen on the passenger side.
  16. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.