can nybody tell me the easiest way to replace the heater core in my 1978 F-150 4x4

your help would be greatly appriciated

 

Look here:

https://www.ford-trucks.com/article/...es_Trucks.html

 

Does it have factory a/c or not? That changes everything.

Marty

 

my 79 SC has factory ac and a bad heater core. how much more trouble does that add to the equation? where's the best place to get a new core?

dave

 

took me about 6 hours to change the heater core in my 79 f250 with factory ac. Got my core at kragens for forty bucks and there was no core charge

 

i bought my core at a place nearby me, cost me 20$ and without air it took about 1.5 hrs working slowly to get it changed.

 

anything not listed in the tech forum i should look out for having factory ac?

 

Biggest problem I remember having (not counting the contortionist related back problems) was the condensation drain tube hanging on the edge of the hole in the inner fender well. I removed the whole shebang from the engine compartment so I could give it a good going over and cleaning. Once the clamp and the short rubber drain tube was removed, the unit came out pretty easy.

 

yea, my ac isn't charged right now so i don't mind taking the whole thing out anyway and maybe replacing some weatherstriping or such.

dave

 

When I went into mine I changed out the blower motor also.

 

is the factory ac under dash or outside the engine compartment

 

engine compartment.

 

oh yeah i remeber those days, the pickup i got now is under the dash i think its way easier. might as well replace what looks bad while your in there, im sure you dont want to tear it apart this winter.

 

As others have mentioned the procedure is different depending upon if you have a/c or not. For non-a/c trucks you can get detailed instructions from a Haynes book, which is a worthy investment. It's probably covered in the shop manuals on Cd available here.

The job is basically a pain because you have to do the following:

1) drain your coolant
2) remove your glovebox liner
3) detach the heater control cables from the heat/vent box
4) remove the heater hoses from the firewall side
5) disconnect the blower motor from the firewall side
6) remove the nuts holding the heat/vent box to the firewall from the firewall side.
7) pull out the entire heat/vent box assy. from under the dashboard.
8) remove the heater core (mental note: it will still have some coolant in it)
9) replace the heater core (it will be pretty obvious how to go about that)
10) you SHOULD replace the blower motor at the same time just because.
11) reassembly is the reverse of the above.

And don't forget to refill your coolant.