The heater core in your Chevy Silverado helps regulate the temperature inside the passenger compartment. The core uses the heat from the engine cooling system to warm the air around the core, which than is blown inside the cabin. It's a very convenient system during the winter months. But an old heater core may become damaged, leak into the floor under the dashboard or stop providing warm air. Replacing the unit on your Silverado model is an involved process since you need to remove the HVAC assembly. Still, this is a job you can accomplish at home.
Removing the Heating, Ventilation and Air Conditioning (HVAC) Assembly
Before you can remove the HVAC assembly, if your particular Silverado model is equipped with air conditioning, take your pickup truck to an approved facility and have them discharge the refrigerant.
Back in your garage, wait 30 minutes to an hour for the engine to cool. You will need to drain the cooling system. Opening the radiator cap when the engine is hot will cause the fluid to spray out with force and cause you serious skin burns.
When ready, drain the cooling system and remove the auxiliary battery. Then, you can remove components in this order for easier access to the core: Detach the air conditioner's accumulator, remove the evaporator drain hose and disconnect the HVAC system's electrical and ground connections. Working from inside the cabin, unfasten and remove the instrument panel carrier. Then, from the engine compartment, unfasten the bolts and nuts that hold the HVAC assembly to the firewall and remove the assembly.
If you have not done so yet, disconnect the hoses from the heater core in the engine compartment.
Removing the Heater Core
With the HVAC removed, unfasten the heater core cover from the top of the HVAC and remove the cover. This will give you access to the heater core gasket. Once you remove the gasket, you will be able to remove heater core from the HVAC assembly.
Follow the opposite procedure to install the new heater core. Secure the core to the HVAC assembly and reinstall any other parts you had to remove.
If you are filling the cooling system with a new mixture, use distilled water instead or regular water to mix with the new antifreeze. Distilled water makes it harder for rust and lime to build up inside your radiator and heater core, helping to increase its service life.
