Q: How to remove and install the heater core on Ford Excursion?
A: On 2008 and later models, the heater and Evaporator cores are mounted in a large housing under the instrument panel. The instrument panel must be removed for access to the housing, and this is a difficult procedure for the home mechanic, involving many hard-to find/reach fasteners and electrical connectors. It is recommended that heater core replacement for these models be performed at a dealership. For removal, first drain the cooling system. Then, disconnect the heater hoses from the heater core pipes at the firewall. Clamp off the hoses to prevent coolant from leaking out. To disconnect each hose, push it toward the heater core pipe to fully expose the locking tabs, compress the retainer locking tabs, and then, using a slight twisting motion while simultaneously pulling on the heater hose, pull the hose off the heater core pipe. After disconnecting both hoses, remove and discard the coupling retainers. Always use new retainers when reconnecting the hoses to the heater core pipes. Next, push in the stops at the left and right sides of the glove compartment door, then lower the door. Remove the panel/floor door vacuum control motor. Then, remove the electronic blend door actuator mounting screw and position the blend door actuator assembly out of the way. Remove the heater core cover screws, raise the heater core cover, then remove it. Finally, remove the heater core from the heater core housing.For installation, the process is the reverse of removal with the following notes: Before installing the heater core cover, add a gasket between the housing and the cover. Fill the cooling system with the correct type and amount of coolant. Start the engine and check for leaks.