Im rebuilding the a/c box in my 65, and was just wondering- how do you solder the one heater line to the valve without melting the o-ring in the other heater line? Also. does anybody have a diagram of one of these boxes? I have a rod missing from the valve to the door and an opening in the outside of the box, looks like a second relay(?) goes there. Has screw holes next to it, but nothing in it. -Pat

I'd try to hunt down an original service manual for that car. It will come in handy. And search around for C-body specific forums. Those guys will know.

Solder which line? Are you replacing the valve inside the box that essentially splits the core in two? The A/C setup is not covered in the FSM just in case you don't have one to check, there is a separate factory training manual that does cover it well but right now I can't think where my set of those is at.
Mike

If that second opening with the screw holes next it is in the bottom passenger side that's likely where the heater control valve sensor fits in. Do you still have the heater control valve located in the firewall just below the seam on the right side of the passenger footwell? On another note - where in the world did you find a heater core that will accept the inner control valve? I haven't seen any replacement cores that will in the 39 years I've been working on a 65 C body. I do have a couple of those valves, but they're mostly a curiosity for now.
Mike

Just went and took a pic, here's the control valve sensor - the plain steel colored plate with the copper tube coming out from under it, that tube runs to the valve.

Yes, thats what is missing on mine- the control with the copper tupe coming out of it. Also the rod going from the valve to the door is missing. I didn't have to find a core, mine tested good at a radiator shop. Man there said it had been re-cored sometimes in the past. Here's a pic of what I'm working with. You can see one of the lines has an o-ring, but the other one doesn't. I assume it is soldered to the pipe coming from the core?

The valve in the middle is connected to the piping by rubber hoses, and I found the manual that explains that when the a/c is turned on that valve bypasses 70% of the heater core, the link connecting that valve to the damper door is what controls the bypass. The in/outlet are connected to piping going through the firewall by sliding them on, both tubes use an o-ring and the firewall connector just slides on and screws to the housing if I remember rightly. (The screws to the housing is the iffy part of my memory banks tonight.) I do have one of those connector pieces laying loose to photograph tomorrow if you need. Here's a shot of the water control valve tacked on. (Just looked at the picture of yours again and see the firewall connector laying above the core - it just slides on those two tubes. It's been so long since I've had mine apart I can't say for sure if there's supposed to be an oring on both tubes or if one's in the firewall connector piece.

The tubes just slide on? Only one of my tubes has the o-ring, the other tube was soldered on when I took it apart- I see no place for an o-ring on the second tube. Am I missing something?

I have an extra box on the shelf, let me pop the cover on it and double check. There was no solder on any I've done so far.

this is what I'm working with now

Compared to what I started with

looking real good so far. If it was that bad when you started it's no wonder you're missing parts/pieces and finding things modified.

Pat,
Just scanned in the pages from the manual I mentioned and sent them to the email in your profile. It's all pretty much as I remembered but the pictures and explanations may be of good use to you in your rebuild.
Mike

Thanks Mike! I'll check it now!

OK, I see what the manual says. Problem is, the pic they show has two lines leaving the core, both the same length, and both with an o-ring. Mine has one line longer than the other, and only one has an o-ring. Maybe I should just go dukes of hazzard and not have heat or air...eh, no.

Yeah, it looks like yours has been modified in the past. Maybe when it was recored if your guy is right about that. I used to have an old core around but don't think I know if/where I still do, it would have been good for parts/pieces.

Well, can't find that old core right now. I'd say your best bet would be to try find an old heater box you can scavenge parts from, could probably pull the oring adapter off the other line and install on yours. It's gotta be a whole lot easier to assemble everything if you can install the exterior lines by sliding them in after the box is assembled and mounted. That would also be a good way to find that connecting link that operates the bypass valve. Good luck with it.
Mike

O-ring adaptor? Look at the pic of my core again. Is that what's inside the firewall tube???

No, on the one tube that has the o-ring on your setup it appears to be a nipple of sorts on the end of the tube where the o-ring sits for sealing. I'm thinking that is a soldered on piece that was removed from the upper tube sometime in the past, possibly damaged or something when it was recored as you speculated it had been. I think the easiest fix would be to find an old leaking core that someone has discarded and/or an old complete heater box and just remove that nipple and affix it to your tube. I haven't personally attempted this nor do I know if it's feasible but that sure looks to me like a separate piece that could be r/r'd. That's part of why I was looking for that old core I think I still have somewhere to see if it's a doable thing, if so I'd been thinking to remove it and send it your way. I'm also reasonably sure that core is the same for all 65 - 68 C bodies and I think the same unit for 68 - 70 B bodies; all being A/C equipped of course.
Mike

Well, went out and dug up the spare valve I mentioned earlier to see if that comes with that fitting and indeed it does. It is a brass fitting that slips inside the copper pipe and is soldered in place. I can't find a p/n for the fitting, but the valve including the fitting is 2521 240. There's a couple on ebay right now, but they're on the steep side, parts voice lists a few available but don't know if they're more reasonably priced or not. Oh BTW, the rod from the door to the valve is p/n 2521 246 but I don't see any of them listed. Still think finding a used box may be your best route all around as both parts you need should be there and maybe a couple you don't know about yet.
Good luck with it, let me know if I can muddy the waters any more for you.
Mike

Any luck finding anything? I dug a bit deeper and found that old core I knew I'd saved. Probably still have the control rod I removed also but have no idea which container/box it may be in, it's been a lot of years since I recored my heater and the rod is a lot smaller than a core.

Mike- that was the problem. The o-ring adaptor had come off inside the firewall tube. I soaked it for a couple of days and got it out. It is soldered back where it belongs now. I am going Friday to check out a couple of old heater boxes a friend has, hopefully one has the rod and (maybe) an ac evaporator. The tray on mine has a religious issue. (It is holy). I still need the heater control valve that goes to the firewall but I saw some of those on the bay. Thanks for the help and the follow up- I'll have some pics of it on here when I get a little farther along.

Hey, sounds good. I thought that would be real interesting to try assembling by soldering those two pipes together..