So... after looking at some pictures a couple of days ago that Patrick posted a year or so ago about leaf and debris buildup from the cowl into the evaporator, it's been irking me. My daughter completely rebuilt the entire front-end compartment of her car... it looks amazing:




But I kept remembering two things:

1 - We never removed the evaporator coil to clean it. We just removed the fan-speed coil thingy, and stuck a vacuum cleaner in there.
2 - The air flow coming out of the vents was almost non-existent.


I even replaced the fan itself because I kept thinking that was maybe the problem. It improved it slightly... but still, it wasn't the air flow I was expecting. So I tore most of it apart this afternoon (she didn't see me doing it), and I removed the evaporator (which was a pain in the ass):




I didn't take a picture of everything that was in there. We sucked out most of it from the fan speed coil thing. I kept sticking a tube in there and a coat hanger, and my fingers. There was so much crap, I can't even tell you. It was insane. What you see in the image above was all the other stuff that had been sucked into it... like all the dust and whatever else.

I was just going to buy a new one, but this one pressure-tested ok, and I straightened all the fins and blasted it with air and warm water from the other side. I can now see through the evaporator... so I know it's "good." But I'm kind of pissed we didn't do it sooner. I haven't hooked everything back up yet... so I haven't checked the air flow from the vents, but I expect it to be a lot more than it was.


Anyway, I'm glad I did... but quick question. Anyone know where I can get that Playdough stuff that goes at the top which is supposed to seal the evaporator tube to the HVAC box?


Thanks!

[This message has been edited by 82-T/A [At Work] (edited 10-12-2025).]

quote Originally posted by 82-T/A [At Work]: There was so much crap, I can't even tell you. It was insane. What you see in the image above was all the other stuff that had been sucked into it... like all the dust and whatever else.

"Whatever else"... such as mold, etc.It's really disgusting when you realize that we have to breathe the air that's blown through all that crap. Ughhh!

So even if there wasn't a potential fire hazard, there's probably plenty of health reasons alone to clean all that debris out of the HVAC assembly.

quote Originally posted by Patrick: "Whatever else"... such as mold, etc.It's really disgusting when you realize that we have to breathe the air that's blown through all that crap. Ughhh! So even if there wasn't a potential fire hazard, there's probably plenty of health reasons alone to clean all that debris out of the HVAC assembly.

There was probably enough crushed leaves and dirt crammed in there that it could easily fill a 16 ounce coffee cup.

It was nasty...


EDIT: I found some moldable HVAC "putty," which looks exactly like what came in there.

Also... I ended up buying another dryer. The AC lines were left disconnected for like 4 months in the garage in Florida. I did some AC research and realized these dryers have desiccant in them, so I'd basically ruined the dryer. I thought I had a second one, but just had to order a new one. I should have the A/C system totally finished by next week ... just in time for winter, lol...

[This message has been edited by 82-T/A [At Work] (edited 10-12-2025).]

I believe the moldable gray clay putty is called DuctSeal putty.

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quote Originally posted by 82-T/A [At Work]: So... after looking at some pictures a couple of days ago that Patrick posted a year or so ago about leaf and debris buildup from the cowl into the evaporator, it's been irking me. My daughter completely rebuilt the entire front-end compartment of her car... it looks amazing: But I kept remembering two things: 1 - We never removed the evaporator coil to clean it. We just removed the fan-speed coil thingy, and stuck a vacuum cleaner in there. 2 - The air flow coming out of the vents was almost non-existent. I even replaced the fan itself because I kept thinking that was maybe the problem. It improved it slightly... but still, it wasn't the air flow I was expecting. So I tore most of it apart this afternoon (she didn't see me doing it), and I removed the evaporator (which was a pain in the ass): I didn't take a picture of everything that was in there. We sucked out most of it from the fan speed coil thing. I kept sticking a tube in there and a coat hanger, and my fingers. There was so much crap, I can't even tell you. It was insane. What you see in the image above was all the other stuff that had been sucked into it... like all the dust and whatever else. I was just going to buy a new one, but this one pressure-tested ok, and I straightened all the fins and blasted it with air and warm water from the other side. I can now see through the evaporator... so I know it's "good." But I'm kind of pissed we didn't do it sooner. I haven't hooked everything back up yet... so I haven't checked the air flow from the vents, but I expect it to be a lot more than it was. Anyway, I'm glad I did... but quick question. Anyone know where I can get that Playdough stuff that goes at the top which is supposed to seal the evaporator tube to the HVAC box? Thanks!

gm called it dumdum. a moldable putty should be fine but most people on GTO and other muscle cars and trucks like squarebodys use the non hardening liguid nails
i think ive used straight up silicone putty (not the toy stuff) but i dont own that vehicle anymore to tell you how it works
however you can buy butyl rubber sealant and "tacky tape" which is what they use to seal the windshield and that works amazing

quote Originally posted by cartercarbaficionado: gm called it dumdum. a moldable putty should be fine but most people on GTO and other muscle cars and trucks like squarebodys use the non hardening liguid nails i think ive used straight up silicone putty (not the toy stuff) but i dont own that vehicle anymore to tell you how it works however you can buy butyl rubber sealant and "tacky tape" which is what they use to seal the windshield and that works amazing

This is what I ended up ordering: https://www.amazon.com/dp/B008A3UG94

It's a dark grey, almost like a charcoal... so not exactly like the factory, but I think decent enough. I also stuffed the hole with adhesive backed foam insulation too... just so the putty would have something to sit on:




... and the foam strip:

[This message has been edited by 82-T/A [At Work] (edited 10-13-2025).]

My father told me (when I was a teen) that you should always turn the AC off but keep the fan running (Speed "2") to dry out the system...otherwise you will grow mold in there- had a friend with a Mustang shop who would NEVER own/drive a car with AC because it made him sick.