Heater Core Removal and Installation For 1973-1979 Ford F-Series Trucks
By Thomas Hogan
- Disconnect the battery ground cable.
- Remove the air cleaner.
- Drain the engine coolant below the level of the
- Remove the heater hoses from the heater core.
- Remove the screw fastening the A/C hose support
bracket to the firewall.
- The expansion valve is located on the right side
of the evaporator core housing. Remove the insulating tape covering
- Remove the two screws holding the plate over
the opening that the A/C hoses exit the evaporator housing. Remove
the plate and the seal.
- Remove the glove box liner.
- Separate the A/C duct from the register in the
instrument panel and free the clip holding it to the plenum.
Remove the duct from under the dash.
- Remove the vacuum hose from the vacuum motor
on the right hand side of the air box.
- Remove the rear housing cover from the evaporator
housing. The cover is retained by 4 nuts and one bolt. Disconnect
the fresh air tube from the rear cover. After the cover is removed
reinstall one nut to secure the evaporator housing to the firewall.
- Gently remove the capillary tube from the evaporator
core. Disconnect the wires from the icing sensor. Remove the
plate the sensor is mounted to.
- Remove the plenum by extracting the two screws
above the transmission tunnel that hold the plenum to the dash.
- Remove the screws securing the evaporator.
- Pull the evaporator from the case and secure
it above the case.
- Remove the heater core.
- Remove the heater air control door. There are
no screws this is retained by a spring clip and snaps off.
- Remove the arm that supports the air control
door and the retainer that secures the pivot arm.
- Remove the blower motor.
- Transfer the blower wheel to the new motor.
- Reverse the disassembly steps to assemble the
heater A/C box.