not looking for trouble but how often do heater cores on these let loose and how hard a job is it ?? thanks

They don't fail often. And it is hard to change one out. Do a search here to find how to do it without removing the dash.

Recently you were in the area of the heater box cover with your air mix door.

I don't think it'* overly hard.. more of a PITA and tight spaces.

Before doing one I would buy a Craftsman spring hose clamp removal tool and the 5.5mm socket like you used on the air mix stuff.

Boosty'* right. You were practically there when you swapped out the airmix actuator. Same process, only you put both feet on the dash, grab the heater core cover, and yank it completely outta there. You're in virgin territory after that, as far as I'm concerned. I took a look at it while I was in there, and it looks like a fairly simple process to remove the heater core. The hardest part will most likely be installing the heater core cover. A few strategically placed cuss words will help get it back in there.

You planning on doing something that could potentially bring your heater core to its knees? Post pictures if you do. rofl!

If you're worried about your heater core giving up the ghost for no apparent reason, consider this: the heater core on my 1963 Star Chief cashed in its chips (for the first time) earlier this summer. The math is left as an excercise for the student. How old is your car?

They don't fail often, however, I was one of the unlucky few. Mine failed when the car was 4 years old and had only 77,000 miles. At the time, nobody here knew much about changing them out. Since it was new territory for me too I ended up having it done at a local shop. It cost ~$175.

Let'* think this over in steps..and please add in where I forget stuff (I've never done it)

Drain coolant
Use Craftsman tool to remove the hose clamps on the firewall where the hoses run to the heater core connections.
Swear and cuss
Hop inside, remove hush panel on pass side
Remove AC programmer
Cuss more
Pull heater core cover
Remove heater core..

Reverse steps cussing as needed.

Tip: replace cussing with a beer

Pht. When it'* put that way, you should be able to do it in 10-15 minutes, tops! It'* so easy. Good job Boosty! The only other thing I'd suggest is to augment cussing with beer instead of replacing cussing with beer - those who don't imbibe will have much more fun watching you!

In reality, excluding details, that'* all there is to it.

Can't find a picture right now. But IIRC there are only a couple of screws that hold the cover on the end of that heater box. The cover has seals around the edges and hooks into the back end. I do recall someone saying something was difficult about putting the core back in but I don't recall if it was getting the core caulked and placed or getting the cover back into place...

Frankly it looks as easy as repairing a Whirlepool washer or dryer. It all just comes apart with a couple of screws.

True dat, your memory is correct. There'* only 2 screws holding the heater core cover on. The programmer has to come out in order to remove the wretched air mix actuator, which is attached to the top side of the core cover. Problem comes in getting the cover out from under the dash. Very tight. Pulling the carpet and insulation back helps a bit. Same problem getting the thing back in. No need for caulking, there'* a seal on the cover. If the engineers had given us just one more inch of space under there, this would be a breeze!

No, you don't replace cussing with beer, you enhance it...