Pontiac 89018289 Heater Core

To remove the heater core, start by disconnecting the cable from the negative battery terminal and draining the cooling system. If the coolant is still in good condition, it can be saved and reused. Then, disconnect the heater hoses from the heater core fittings at the firewall. Remove the insulating panels below each side of the dash, as well as the front seats, kick plate trim panels, and center console. Peel back the front carpet to access the air duct beneath the center console and detach the floor air duct leading to the rear. Remove the screws and heat stakes holding the outer and inner heater core covers in place, using a small chisel or screwdriver. Finally, remove the heater core from the housing, placing rags underneath to catch any spilled coolant. To install the heater core, simply reverse the removal steps, ensuring to reconnect the heater hoses at the firewall. Refill the cooling system and reconnect the battery.