Heater Core: Service and Repair

Heater Core

Removal and Installation

NOTE: If a heater core leak is suspected, the heater core must be leak tested before it is removed from the vehicle.

Gasoline vehicles

1. Drain the engine coolant. For additional information, refer to Cooling System &/or Engine Block Heater.

Diesel vehicles

2. Drain the engine primary cooling system. For additional information, refer to Cooling System.

All vehicles

3. Remove the instrument panel.

Diesel vehicles with electric heater

4. Disconnect the Auxiliary Heater Control Module (AHCM) electrical connector.

5. Remove the 2 AHCM (Auxiliary Heater Control Module) screws and position the AHCM (Auxiliary Heater Control Module) aside.

All vehicles

6. Remove the 2 heater core cover screws and remove the cover.

7. Remove the 2 heater core tube clips at the heater core and disconnect the heater core tubes from the heater core.
- Discard the O-ring seals.

8. Remove the heater core.

9. To install, reverse the removal procedure.
- Install new O-ring seals.


Diesel vehicles

10. NOTICE: Evaluate the cooling system condition before filling the engine cooling system. Failure to follow these instructions can result in damage to the engine.

Evaluate the cooling system condition. For additional information, refer to Cooling System Condition Evaluation in Cooling System.

Gasoline vehicles

11. Fill and bleed the cooling system. For additional information, refer to Cooling System &/or Engine Block Heater.