ElGuapo1975

Greetings! Does anybody have a definitive answer on how to change out the heater core on a 1985 F-150? Mine is a straight 6, No AC, RW Drive, 8 Foot Bed, Beater that I picked up for $600.00 3 years ago. It has served me well with only a few replacements. Previous owner replaced much of everything during his time with it. When I turn on the fan I have misting going on in the cab and my windshield fogs up with anti-freeze. I popped the hood and AF was leaking out the intake hoses to the heater core. Spraying out is a better description. It stops when I shut the fan off but I still get some clouding in there while driving around with no fan on. I assume the heater core needs to be replaced. My problem is I don't know the best way to access the old one and put in a new one ($29.99 at the local NAPA). Some internet research suggested removing the glove box insert and accessing it that way but when I did, I came across a big plastic housing that does not meet the online descriptions for simple Heater Core access. And that housing has no where to go even if I do get it out. I have removed two screws (above and below) to loosen it but it doesn't appear to want to move. What am I missing here? Is there a better way to access it short of removing my dashboard to get better access for removing that housing? Under the hood maybe? Any help or suggestions would be greatly appreciated. Thanks! Tom

GhostriderI

Is the passengers side floor wet? If not it may be the hose is cracked at the connection and spraying in to the heater box. Just a thought

GhostriderI

If you still need to remove the heater core. Here ya go.

1. Disconnect the Temperature cable from temperature blend door and the mounting bracket on top of the heater case.
2. Disconnect the wires from the blower motor resistor and blower motor.
3. Disconnect the heater hoses from the heater core and plug the hoses with suitable 5/8 inch (16mm) plugs.
4. Working under the instrument panel, remove three nuts retaining the left end of the heater case and the right end of the plenum in the dash panel.
5. Remove the two screws attaching the right end of the heater case to the dash panel and remove heater case from vehicle.
6. Remove eleven screws and one bolt and nut attaching the heater housing plate to the heater case and remove the heater housing plate.
7. Remove the heater core and seal from the heater case.


This will get it out. Installation is just as long a process

Once you position the heater core and seal into the case reverse the process above.

ElGuapo1975

Thank you Ghostrider.
The passenger floor was not wet which would be great if it just comes down to hoses. That would be an easy place to start Should probably do that anyway if I do have to replace the core.

Pardon my lack of understanding for car terminology but is this an under the dash job or under the hood job?

The instructions you gave seem to the point and I should be able to follow them given your direction.
And I will try this week when I get more time.

If this gets too much, what about the bypass option?
I don't need heat in there since I don't really drive far distances with it and especially not in the winter?
I would just have to avoid rain too so I don't get fogged out and need defrost.

I am a car repair n00b on anything but this truck.
But I have successfully replaced the starter solenoid and ignition switch in the steering column. Yay!

Thanks again.
If there is anything else I should note please let me know.

GhostriderI

Straight out of the Chilton's manual


as with anything the more you do the better you become...

The heater hoses are under the hood, as far as the fan connections I do not know as mine has a/c, but, every thing else should be under the dash and yes there are some screws that will be easier to access through the glove box if removed.

Good luck and feel free to ask any questions.

GhostriderI

Bump, How did it go?

ElGuapo1975

Thanks for the help and sorry for the delay.

I started to disassemble underneah the dash according to the instructions given above when I quickly realized that there was a lot more going on in this job than I could handle.
Patience, time, weather and me starting a new job have put this project on the backburner.

My plan this weekend is to just give the heating system a bypass and call it a day.
I saw something online about just using a small piece of PVC pipe to do it with.

Since I don't travel distances in the winter with it I am fine with wearing a heavier jacket on my way to/from the dump, friend moving day, or appliance store.
And during the rest of the year I try and avoid rainy day driving with this beast.

I wish I had a good heater core replacement story for everyone.
Napa has them for $30.00 so it wasn't the cost.
Just my experience and patience under the dash.

I will update on how the bypass goes.

Thanks again everyone.

Tom

zer0vector

Guapo...I hope you see this reply because I ran into the exact issue you did, heater core replacement on a 1985 Ford F150. The problem with all the directions I found online is that they were for the model with AC, which mine, like yours, doesn't have. In those, the heater core is mostly under the dash but in ours the heater core unit is entirely under the hood and the removal is a very different process. You'll still need to remove the glove box to get at some of the bolts from the passenger compartment side, but that should be about it. Some of them are hard to reach, and having a friend really helps, but it is a totally doable job. If you still want to give it a try I can take some pictures of my truck and post them to help out where all the bolts are. Let me know.