How to Replace a Heater Core in a 98 Chevy Pickupby Robert Kohnke; Updated November 07, 2017
Items you will need
Socket wrench set
Pan for radiator fluid
Towels to plug hoses
A heater core is used in the heating of the cabin of a vehicle. It is a radiator-like device that takes hot coolant from the vehicle's engine and passes it through the winding tube of the core. The heat transfers to the tube, which then heats the air that passes through it on its way to the cabin. If the heater core in your 1998 Chevy Pickup isn't working properly, it is an easy enough fix that can be done in less than half an hour.
Use the open-end wrench to disconnect the negative battery cable from the battery.
Open the radiator release valve on the bottom of the radiator and drain the coolant liquid into the pan.
Remove the mounting bolts from the modular duct using a socket wrench. These bolts can be reached from the inside of the glove box compartment, in the passenger side of the cabin.
Remove the modular duct from the glove box compartment.
Disconnect the heater hoses from the heater core. Plug the hoses when they are disconnected.
Remove the mounting bolts from the heater core with the socket wrench set. Remove the heater core next.
Install the new heater core in the place of the old one and reattach the bolts. Replace the modular duct and the hoses. Fill the radiator with a 50-50 water and coolant mixture.