Fresh Air Door Seal Issue

WHYTLIE

Not-quite-so-new-guy
Sep 24, 2023
12
47
13
Lincoln, CA
I tried searching and didn’t come up with anything similar. I’m “rebuilding” and resealing my son’s HVAC box from his ‘86 El Camino. I bought the HVAC seal kit from Mike’s Montes. New AC evaporator, drier, new heater Core, new blower, resister, and relay. Going to replace the compressor, AC lines, and condenser in the upcoming month and hope to have the AC working with 134a. The new evaporator came with a new orofice tube. Kinda a bummer as I’m hoping next summer we can do the 6.0l 4L80e swap and that will require new AC lines and a new condenser then (for pass side AC lines).

First off, this car has some tar or sealant at the base of the windshield and on the firewall that is a bear to get off, like wire wheel and paint scraper or chisel job.
IMG_0251.jpeg

Finally got the HVAC box clean and back together. A HUGE thank you to HutchHiPerf and his YouTube videos!

My issue is that the fresh air door and the new seal from Mike’s Montes don’t match up.
image0.jpeg


The hole pattern is different and the holes that are there don’t line up. I did not realize this until I’d removed the original seal, which in hindsight I wish I’d left as it was in pretty good shape.

I emailed Mike and asked if he’d come across this or if he had a suggestion and his response was, “I have sold 250 of these first time anyone has said this”.

So now I’m stuck either gluing this new seal to the door or trying to find a door with the proper pattern.

Searching on here and the internet in general I haven’t found a pic of a bare G-Body fresh air door to compare.

Anyone have a picture of their fresh air door you can share? Anyone else run across this? If so, how’d you solve it? Just glue it on there and check for sealing once it’s glued on?
 
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Ugly1

Royal Smart Person
Oct 26, 2021
1,636
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Lost in the woods of NH
The sealant/tar is a factory urethane sealer ( available at body shop supply store) and is needed or you end up with lots of water on the floor. My car was non A/C so I used parts off the kit to make one.
You could try an upholstery shop or email the MANUFACTURER of the kit. Mike’s is only a supplier like NAPA… You could try a cloth shop but that’s a big maybe. Be sure to bring a piece for show and tell.
 
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Ribbedroof

Comic Book Super Hero
Supporting Member
Jan 4, 2009
4,900
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113
Wellston, OK
Seems like my 81 had a metal door.

Maybe make a new seal out of toolbox drawer liner?
 
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WHYTLIE

Not-quite-so-new-guy
Sep 24, 2023
12
47
13
Lincoln, CA
The sealant/tar is a factory urethane sealer ( available at body shop supply store) and is needed or you end up with lots of water on the floor. My car was non A/C so I used parts off the kit to make one.
You could try an upholstery shop or email the MANUFACTURER of the kit. Mike’s is only a supplier like NAPA… You could try a cloth shop but that’s a big maybe. Be sure to bring a piece for show and tell.
The substance I’m referring to does not seem to be applied anywhere it would prevent water from intruding into the car. I’ll snap some better pics of it and it’s locations.
 
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WHYTLIE

Not-quite-so-new-guy
Sep 24, 2023
12
47
13
Lincoln, CA
Seems like my 81 had a metal door.

Maybe make a new seal out of toolbox drawer liner?
A metal door on earlier models makes sense. I know HitchHiPerf had what looked like the same white, plastic door. He smartly decided to reuse his door with the factory seal. The seal in the kit appears to be sized appropriately for the opening in the “cage” of the HVAC box. It will just be tricky gluing it to the door and making sure it’s aligned properly to seal well. And the seal in the kit has an appropriate thickness and stiffness to do the job.

Thanks for the input, fellas.
 
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Ugly1

Royal Smart Person
Oct 26, 2021
1,636
1,369
113
Lost in the woods of NH
While you’re working on the heater box make sure the little rubber flap is clear of any old debris so the water can drain out. It’s at the underside of the box on the engine side. Though you probably already have being that deep into the job.
 
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WHYTLIE

Not-quite-so-new-guy
Sep 24, 2023
12
47
13
Lincoln, CA
While you’re working on the heater box make sure the little rubber flap is clear of any old debris so the water can drain out. It’s at the underside of the box on the engine side. Though you probably already have being that deep into the job.
Oh yes! Ours was caked with dirt, and one good rain would have either cleared it out or backed up into the brand new carpet. I managed to get the little rubber door off safely and spent a good while cleaning it off. Looks as good as new, for a nearly 38 year old rubber part.
 
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86 Salon

Apprentice
Mar 14, 2021
69
73
18
On my 1973 GS,I used sill seal from Lowes. It sealed perfect. It's blue, but you can't see it when installed.
 
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