Finally got around to replacing the heater core in my 1980 F350 Custom 400 cid no air conditioning. Here's the sequence:

Remove the glove box. You'll find several screws in the top and bottom of the box, 2 screws that retain the glove box door cables. I also removed the glove box door from the hinge in order to get a clearer shot at the heater core/fan assembly bolts inside the cabin. I also lubed the glove box door hinge:



take care removing the glove box, its made from fiber board and could be very fragile.



Remove 3 nuts from inside the cab :

the nut on the top (center of the assembly) right, inside the cabin. the bolt below it is the bolt that will be removed from inside the engine compartment later.



remove the nut from the top left (pic taken of the bolt hole after the assembly had been removed). there is one directly below this one that you have to remove



remove nut from bottom left (this pic shows the bolt holes, bottom left and top right) after the assembly had been removed:



Remove the blend door cable:





Unplug resistor:



Unplug Blower Fan:



Remove 3 bolts from engine compartment/firewall:

1 in the top center of the assembly:



1 on the top left of the assembly there is one on the bottom of the assembly to be removed (not shown):



Pull entire assembly away from firewall:



Here is the assembly removed from the vehicle, note the debris that has accumulated over 30 years!:





Remove retaining flange:







Assembly with retaining flange removed:



Remove heater core retaining bracket, 2 screws on top, one on bottom:







Remove heater core:



Note the difference in the old and the new (NAPA part). The new core is much lighter and has very cheap gasketing:



All the blend door gasketing had deteriorated so I removed the blend door to replace the gasket which i made:







I didn't replace the gasketing as per OEM. I simply cut pieces from some foam I had lying around to fit the blend door perimeter and frame. You just need something to create a decent seal and not hamper blend door movement:







Here's the blend door back in place showing how I made the seal. Check for proper blend door operation and make adjustments in the gasketing if needed:



Now time for the new heater core to go in:





Replace the heater core retaining bracket:



Replace assembly retaining flange:



Mount Assembly to firewall:













Replace nuts on bolts from inside cab:



Replace glove box:



Reattach blend door cable, plug resistor and fan motor back in.

It would be a good idea to replace the heater hoses, clamps and thermostat at this time. Add antifreeze if needed.

Start engine, check for leaks, set heat to the max setting, turn on the fan motor and you should have hot air coming from your heater.

 

I've been there and done that. Except, I don't remember if I took everything all the way out or not (it's been quite a while back).

 

As I understand it, the whole assembly must come out only on models without AC.

 

Thanks Kraylake getting ready to do this on my 84 your pictures and right up is very refreshing thanks

 

This definitely needs to go up in the how-to sticky. I see you put the pictures on this site, so that's good. Just make sure not to move them around and they should stay with this thread.

 

I agree, and so I put it into there.
https://www.ford-trucks.com/forums/8...ml#post7634517

Replaced a previous entry in which the OP deleted the pictures from the hosting site, so out goes that thread and in comes this one.

Somebody please rep kraylake for me, I need to spread the love...

 

Thank you for your effort in putting all that together, that was excellent!

 

Very detailed write up, and the pics really help to show where the various fasteners are located.
I applaud your effort. + Rep'ed