I've currently got my heater box out of the car for refurbishment as can be seen in my thread here:

Heater box (HVAC) refurbishment. Are my mode doors correct?

The aluminum heater core is such a PITA to install into the box. I can't even imagine trying to install the core into the box if the box was already installed under the dash. Can I install the heater core into the box and then install the entire assembly into the car? Something tells me that the answer is "no" but I thought that I'd ask and find out for sure.

 

Nope...

 

OK. I didn't think so.

 

Can't imagine the factory crawling around under the dash of cars on the production line trying to install it that way. GOTTA be a way to put the core into the box and install the whole assy. It's been some decades since the last time I had to do that to mine but I seem to recall that I put the core in the box first, then put it all back into the car.

I would bet money that the whole thing - blend doors, the ducts that are screwed to the housings, the wiring, the control head, the whole enchilada - was installed at the vehicle assy plant as a single unit, in the same takt time for any station and assembly step on the line.

Exactly why does it seem like it would be hard to do it that way?

 

Currently, my heater core is inside the heater box. I re-foamed the doors in the box.


You can see the aluminum heater core in place. New foam on the doors.


Sofa, I'm ***guessing*** that parts of the dash are probably not in place on the assembly line allowing the full, completed heater box to be installed. I'm just guessing.

It's such a PITA to get that heater core in there. The actuator arm from the vacuum servo to the top door (with the hole in the foam) was completely in the way. I removed the servo completely to make it easier to get the heater core in. It was much easier without that arm in the way.

It sounds like I have to install the empty heater box first then the heater core. That means that I have to have the vacuum servo installed with its actuator arm in the way making a PITA and even bigger PITA!

 

That's almost certainly true. I never was in a plant for these cars, but that's the order that other cars I've seen are built in.

The ENTIRE dash goes in and comes out in one gigantic piece, if the dash pad, column, and console aren't there. With the car in that state it's not 15 more minutes of work to pop it out or to put it in. (production line takt time, anyone?) There are about 5 or 6 nuts and bolts that hold various places of it to the car; one at each end of the metal brace across the bottom of it which comes out with it, and a few across the top, that hold in some brackets and whatnot. The whole wiring harness also comes out with it, including the fuse box, Fisher body connector, plugs to the column and radio and so on, and pigtails that supply power to the ECM, HVAC, etc. It would make sense for the heater to go in before that on the production line.

Since you've got the car all kinds of torn down anyway, might not be a bad idea to pop the dash out and see how it all goes together; maybe clean up whatever there is behind it that's a mess. I seem to recall some foam, adhesive stuff, tape, and so on, that were rather deteriorated in my car, back in the 90s when I had to do the heater core the 2nd or 3rd time. There was a rash of SUPER CRAPPY heater cores on the market back then and I got seriously bit by that.

 

The inlet & outlet tubes on replacement heater cores are seldom perfectly aligned with the holes in the firewall. I replaced mine in 2018 and it was pretty easy BUT there was no engine in the car at the time. I had to slightly bend the tubes from the engine compartment side of the firewall by inserting a 3/8" socket extension. 'Probably can't do that with the engine in place...

 

Easy enough... just stick acoupla feet of somekinda tubing on them, put that through the holes, complete the installation, remove the tubing once it's all in place... you could even put your new heater hoses on there, without clamps of course until it's all the way in, and cut em to length at the engine end to finish up...

 

Cool idea...

 

The engine is out of the car as I'm LS7/570, Tremec T56 Magnum F swapping it. I finished painting the engine bay a couple of weeks ago in the 95F Houston heat. Lesson learned; never paint in that kind of heat! It did turn out pretty good but there are dry spots in the clear coat that I'm not happy about. Mostly in hard to see places. Everything that is nice and visible is very glossy.

 

I HATE work. I especially don't like to work hard. I don't even really want to work smart. I don't actually want to do ANY work AT ALL if I can help it. I want to sit back, crack a cold adult beverage, and make the work do itself.