Hello everybody. I don't have any heat in my 86 f250. One hose going to the heater core is really hot and the other one is not, so I'm thinking that the core is plugged up. My main problem is, though, the heater core is not where any video or where anyone else has told me. They all say it's behind the glove box. I took the glove box out and I'm not seeing it. Now this truck did have AC at one point. I open the hood and it appears to me that the heater core is right there on the outside of the fire wall encased in some sort of plastic plenum. The heater hoses go right there to this and are hose clamped right on there. Now the other thing is, I don't see any screws holding anything together. I just want some help before I go tearing into things.
Thanks

 

This is what it looks like from underneath the hood.<br/>

 

 

Cable actuated damper.
Dealer installed AC.

That heater core is a PITA compared to behind the glove box.

 

How do I get that heater core out of there

 

See that rusty nut in the upper left corner? Take that off. Feel around for for any more, There may be more on the outside. Then get inside under the dash and take the control cable loose, and there are several screws inside also. See that rusty thing in the middle that looks like a rivet? I think that is a stud that goes into the inside with a nut on it. Once you get it all loose, you have to pull the whole plastic housing off the firewall, fan and all. Of course you have to drain the coolant and take the hoses off.

Before you do all that, why not drain the coolant, take the hoses off the engine, and then take a water hose and stick it to one of the hoses and see if you can get it flushed out. Try both hoses and see what happens.

 

Swap the hoses so the coolant flows opposite through the heater, run it like that for a few days and see if it doesn't cure the problem. Saved me a whole lot of hassle with a Dodge Intrepid heater core. ~Bill

 

This will probably answer all (most) of your questions:

https://www.ford-trucks.com/forums/7...ater-core.html

 

Like it was stated above, I pulled both hoses off at the engine and flushed both ways. After that it worked perfectly.

 

Ok. I've taken the hoses off and flushed the core with a garden hose. I got quite a bit of crude out of the core. I hooked everything back up and I had heat for awhile, but after awhile i lost my heat again. Now I'm back to one of the hoses being really hot and the other one I can hold in my hand. Did the heater core plug back up?

 

Probably. Did you flush it both ways?

 

No, I only flushed it one way. I will try flushing it both ways tonight.
Thanks

 

Try flushing the block too.
Rust and debris will just circulate and clog it again if you don't.

How much is a coolant filter?

 

Well tonight I reflushed the heater core both ways this time. I got some junk out and then I let it run clear for s few minutes. I had really good flow. I refilled the system with antifreeze and purged the air and got the truck up to temperature. I still have the same problem. One of the hoses is so hot I can't grab it and the other is just warm. Any other ideas? I feel like I have good flow through the heater core. I had a garden hose with a spray nozzle and it took everything the hose could give it.

 

If you haven't already done it do like ArdWrknTrk said, flush the block and even the radiator, both ways. There may be stuff flowing from them into the heater core. I don't know for sure if it matters (someone on here probably knows) try swapping the hoses and let it flow through the heater the other way.