EM heater box rebuild?

[joelsplace]

My '62 that I've been driving is overly enthusiastic about heating the car. It won't turn off. The fan turns off but the heat lever doesn't do much if anything. Fan off and heat lever up it still blows a significant amount of heat. This is going to be a problem with the A/C.
It has been a while since I rebuilt one of these heater boxes and my memory isn't working great. I've always done it when I had the engine out. Is it easier to drop the engine or remove the interior panel?
Does the heat door have a rubber seal? I can't find anything on Clark's but the felt insulation. Can I use inner tube or ???

[Dennis66]

I'll be watching this thread. I just had all my cables out a couple of weeks ago and now everything moves smoothly. I did notice how grungy the heat box looked and thought "Maybe I should have taken that out and cleaned everything up while the engine and trans were out of the car". Hindsight. It doesn't look like a lot of fun to remove an EM heat box with the drivetrain in the car. Dennis

[toms73novass]

Joel, I think a piece of neoprene would handle heat better. If I remember correctly that "rubber" is on the air diverter box in back. Ill see if I have pics of one of my rebuilds.

I looked, did not find any. If I remember correctly there is a piece of rubber sandwiched between two metal plates that make up the seal mechanism.

[joelsplace]

That's what I was guessing. Thanks for the confirmation.
Now the question is drop the power train or pull the interior panel?

[Frank DuVal]

I just drop the lower shrouds in the summer..... No heat blowing into the car.

I don't think you can get to the heat flapper in the box from inside the car.

I find most flappers (heat, vent, etc) on cars over 20 years old need attention no matter the make. Just another restoration task, hence my shortcut...

My 66 4 door leaks more around the door glass and door weatherstripping than heat leaking in. Got the AC cranking all the time in the summer.

[joelsplace]

With the heat off mine is warm in a couple of miles when it is 30 degrees outside. No way the A/C is going to be able to overcome it.
I think you can get the entire heater box out from inside the car by removing the panel. I've never done it that way so I may be way off.

[joelsplace]

I pulled my heater hoses off and it blows almost as hard and is still quite a bit above ambient temperature???
I guess there is a high pressure area around the heater box and the transaxle is heating the air?
It is much cooler and smells better than before but still is going to overcome the A/C in the summer. I guess I'll buy some rubber 4" plumbing caps to block the inlets.

[RexJohnson]

Remove the nozzles from the engine and try putting a few lays of aluminum foil between them and the engine. A pie pan from Costco might also work. That is what I use to plug the upper 3" hose.

[Frank DuVal]

Wow! Are you sure the flapper door is closing, even with poor seals?

[joelsplace]

The cable moves the arm and I made sure the arm is against whatever stops it. Maybe the door came loose from the shaft but I would think the arm wouldn't stop then. It does flow less with the lever up so I'm guessing the seal is just completely gone.

[manvair]

Mice ate the edge of the seal in my LM, I fixed it with disks of EPDM sheet and aluminum plate pop-riveted to one side of the existing flap. Oh, and the flap was bent into a broad V shape by being forced closed against mouse nests, etc. This meant that it could not close properly in either direction.

[caraholic4life]

Mice ate the edge of the seal in my LM, I fixed it with disks of EPDM sheet and aluminum plate pop-riveted to one side of the existing flap. Oh, and the flap was bent into a broad V shape by being forced closed against mouse nests, etc. This meant that it could not close properly in either direction.

I also had the edge of the seal on my LM chewed by mice. Fortunately I was able to acquire a good used one at the Corvair Ranch.

My next Heater Box rebuild will be for the Greenbrier at some point.

[guthrie1068]

You guys are going to make me take mine apart now since my engine is out. I should have done it the first time I had it out but I was in a big hurry. Mine seems like it is working fine, but I'm sure it is a mess in there. Here we go...