Heater Core: Testing and Inspection

1. Remove the heater unit.
2. Remove the heater core from the heater unit.
3. Inspect for cracks, damage, and coolant leakage. If any are found, replace the heater core.
4. Inspect for bent fins. If any are bent, use a flathead screwdriver to straighten them.
5. Verify that the heater core inlet and outlet are not distorted or damaged. Repair with pliers if necessary.