Q: How to remove a heater core for your Toyota Corolla?
A: To remove the heater core, start by disconnecting the negative cable from the battery and draining the cooling system. Then, disconnect the heater hoses at the firewall and remove various components such as the center console, glove compartment, and instrument panel. Disconnect major electrical harnesses and remove all fasteners securing the cross-cowl support tube to the cowl and the lube-to-floor brace. Next, remove the HVAC housing unit from the firewall and pull the heater unit out just enough for the heater core tubes to come through the firewall. Finally, remove the heater core from the housing and catch any coolant that may drip. To install, simply reverse the removal steps, refill the cooling system, and check for leaks and proper system operation.