GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 612641  Size: MH
  1. Drain the engine cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Release the clamps of the heater core inlet hose.
  3. Remove the heater core inlet hose at the bulkhead (1).
  4. If the vehicle has a 1.0L engine, remove the heater core inlet hose at the intake manifold (8).
  5. If the vehicle has a 1.3L engine, remove the heater core inlet hose at the thermostat housing (4).
  6. Remove the heater core inlet hose.
  7. Release the clamps of the heater core outlet hose.
  8. Remove the heater core outlet hose at the bulkhead (2).
  9. If the vehicle has a 1.0L engine, remove the heater core outlet hose at the radiator inlet hose (7) above the transaxle.
  10. If the vehicle has a 1.3L engine, remove the heater core outlet hose at the radiator inlet hose (5) above the starter.
  11. Remove the heater core outlet hose.

Installation Procedure


    Object Number: 612641  Size: MH
  1. Connect the heater core inlet hose to the bulkhead (1).
  2. If the vehicle has a 1.0L engine, connect the heater core inlet hose to the intake manifold (8).
  3. If the vehicle has a 1.3L engine, connect the heater core inlet hose to the thermostat housing (4).
  4. Secure the hose with clamps.
  5. Connect the heater core outlet hose to the bulkhead (2).
  6. If the vehicle has a 1.0L engine, connect the heater core outlet hose to the radiator inlet hose (7) above the transaxle.
  7. If the vehicle has a 1.3L engine, connect the heater core outlet hose to the radiator inlet hose (5) above the starter.
  8. Secure the hose with clamps.
  9. Fill the engine cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.