Removing the Heater

• 1). Remove the front seat from the cab to allow better access to the heater. The seat is held in place with two bolts on each of the seat rails.
  
  
• 2). Open the glove box door. Remove the hinge-arm screw and screws across the bottom of the door. Remove the door. Remove the screws that hold the glove box liner in place and remove the liner.
  
  
• 3). Loosen and remove the trim screws that hold the heater control panel to the face of the dashboard. Reach behind the dashboard and depress the retainer clip on top of the control unit. Pull the unit through the face of the dashboard. Disconnect the electrical wires. Set the control unit aside.
  
  
• 4). Reach behind the dashboard and push the hooked ends of the right and left heater control knobs out of the control levers on the heater box.
  
  
• 5). Locate two heater core hoses that attach at the back of the heater box. Loosen the hose clamps with a screwdriver or nut driver. Pry the heater hoses off the brass nozzles with a screwdriver or flat pry bar.
  
  
• 6). Remove the upper and lower vent hoses from the left end of the heater box.
  
  
• 7). Remove the bolts used to mount the heater box. Take the unit out of the truck and place it on a workbench.
  
  

Rebuilding the Heater

• 1). Replace two ring gaskets on the defroster vents at the top of the heater box with the gaskets from the heater seal kit.
  
  
• 2). Remove six screws on the fan blower flange. Pry the fan blower off the heater box with a screwdriver or chisel. Replace the rubber ring gasket behind the motor with the ring gasket from the kit. Reattach the fan blower. Turn the heater box around.
  
  
• 3). Remove the screws on the heater core access plate. Pull the plate off and set it aside. Remove the screws at the base of the heater core inside the heater box. Take out the core. Purchase a new or used core, or have the core refurbished by a radiator shop technicians.
  
  
• 4). Install the new or refurbished heater core in the heater box. Reattach the access plate. Reinstall the heater box in the truck in reverse of the removal procedure.