Heater core question
Postmaster
Joined: Jul 2005
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Removal and Installation of Heater Core Assembly
First, use zip lock bags to store screws and nut as you remove screws and nuts, this will help you keep things organize during removal and installation of hardware.Read instruction, before purchasing parts needed.
Parts need: 1 heater core, 2 gallons of antifreeze, 1 RTV silicone rubber or 1 weather strip adhesive, 1 heater fan motor (recommended), anti seize compound for radiator hoses.
- Loosen peacock on radiator to drain the radiator fluid from the radiator. Use a container to store the radiator fluid (antifreeze). Tighten peacock when fluid has drained.
- Remove glove box door, 2 hinges, 2 screws per hinge, and the cable which attaches to the glove box door.
- Remove the black glove box behind the glove box door. (use a very short screw driver)
- Move glove box to the left side to access the lower vent door screws on passenger side of truck and remove screws to lower vent door. Remove the lower vent door, use a short and medium phillups screw driver.
- Now remove the black glove box, from the bottom, where the lower vent door was located.
- Locate the heater cables from the heater core assembly (big black unit, mounted under the dash), it is easier to find if you move the selectors for the heat or vent and floor selections on the dash above the radio. At the end of cable, locate the one screw mounted to the heater core assembly, and With a short phillups screw driver, remove the screws at the end of the cables, remove heater cables and tie up and out of the way.
- Locate the floor heater vent, this is locate in the front center lower portion, inside the truck, and is mounted to the heater core assembly, below the ashtray. Remove the two clips with a set of pliers, be careful not to break or chip the heater core assembly when removing these clips.
- On the inside of truck, on the heater core assembly, on the right side (passenger side), under the dash, locate and disconnect the wiring harness that mounts to the big black unit, tie wiring harness up and out of the way.
- In the engine compartment, locate the fan motor, remove the wiring harness and the screw for the ground wire, which attaches to the fan motor.
- Loosen and slide away the the two heater hose clamps mounted to the heater core, at right (passenger side) rear firewall, of the the engine compartment, in the engine compartment.
- Remove heater hoses from the heater core at the rear of the engine compartment. Sometimes it easier to slice the rubber heater hose mounted to the heater core with a utility blade, use a regular screw drive to pry the heater hose away from the heater core. Use a container to catch any radiator fluid (antifreeze) leaking from heater hoses.
- Loosen the three nuts under the engine compartment (they look like 3/8" bolt sticking out of the firewall with a nut mounted to it). One is located on the rear portion of the fire wall and is located behind the right valve cover on the fire wall, most of the time there is a ground wire attached to it, remove the nut to remove the ground wire, and remove the nut behind the ground wire. The other two is located near the fan motor on the fire wall. Remove the three nuts.
- The heater core assembly is ready for removal, in the hole of .
- From the inside of truck. Wiggle and remove the heater core assembly. Patience is a virtue. Have some rags nearby to soak up any radiator fluid which leaks in the vehicle.
- After heater assembly is removed, Find a clean area to place the heater core assembly.
- Locate the heater core and remove the screws and bracket.
- Remove the heater core from the heater core assembly.
- Save the old heater core, you will need the rubber and foam attached to it.
- When purchasing your new heater core, take it with you to the automotive store, to match the old heater core with the new heater core.
- Place the rubbers and foams off the old heater core on to the new heater core. Use a weather strip adhesive or RTV silicone to attached it.
- Before placing the new heater core onto heater core assembly. Remove fan motor screws and remove fan motor. Rinse out heater core assembly with water. Use a cotton rag and bucket of water with Pinesol, to wash the inside and outside of heater control assembly.
Wash and rinse to accomplish necessary results. Dry with a cloth. - Optional and highly recommended. Take into consideration of replacing old fan motor with a new fan motor at this time, you might not want to remove fan motor a year of so from now.
- Installation of heater core and heater core assembly. Follow instructions from step 18 backward to step 7. (if rubber foam needs to be replaced on heater core, use the rubber insulating foam for pipes)
- On step 6, make sure heater cables are adjusted correctly. Then, follow step 5 to step 2.
- Fill radiator, as recommended on label on antifreese bottle, with new antifreeze and water.
- Check for leaks.
- Use anti seize compound for radiator hoses on installation of the hoses, as it will ease have to remove hoses later, if needed.
- Check the condition of heater hose, replace if necessary.
- Replace thermostat if necessary.
- Replace radiator hose(s) if necessary.
- Check for leaks on radiator, fix if necessary.
Junior User
Joined: Oct 2002
Posts: 80
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From: Fargo - You Betcha
I am just in the process of finishing this nightmare of a project on my 1978 Lariat with factory A/C. No doubt about it, this has to be the crappiest job I've ever taken on. Despite all the tech articles that say it can be done...it's tough. I gave up trying to get enough slack in the A/C hoses to remove the condensor from the air box to get the heater core out and ended up disconnecting them. I ended up swapping in a different airbox as well...even a bigger nightmare.
Good luck.
Good luck.
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winginit
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