Rainwater in passenger floor, with a pic...UPDATED DRIVER SIDE PIC

[shinkle]

I'm getting rainwater through the AC damper on the passenger side kick panel. I triple checked it is not coolant. I removed the cowl and screen to check for rust, clogged drains or broken seal with the firewall. All good. Very little dirt and no rust, almost pristine. I put a water hose in the cowl to see it drain and sure enough it comes through the AC damper. The water is draining really good out of the bottom of the truck. The AC damper opens with the AC on "max", closed on all other settings. The water does seep through when closed. I put my hand up in the damper cavity and I think I found the small opening that water drains down from the cowl but if so, it dumps directly into the damper cavity. Surely thats not how the drain was designed because water will easily go into the cab when raining and AC set to max? What else could cause this?

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[Vbb199]

I think you can take in water from the hood hinge seals, at least thats where I think water leaks in my suburban . I might be wrong. I have the same issue, when it downpours

 

[AuroraGirl]

14043794 - 1981-91 Chevrolet, GMC Truck; Hood Hinge Cowl Panel Water Deflector; RH

Reproduction of the original hood hinge cowl panel water deflector for 1981-86 C/K and 1987-91 R/V truck and SUV models. Each deflector is produced in vulcanized rubber over a stamped steel substrate.

www.classicindustries.com

 

[Joshua Keith]

@Vbb199 The cowling is open rain water so what exactly do these hinge seals prevent?

 

[bucket]

If water is coming in around there, you need to remove the damper assembly and reseal the backside of it. It is open to the cowl drain, so it has it's own seal to keep water from coming in.

 

[shinkle]

But the damper opens when AC is set to Max to let water in. How will resealing the damper backside stop it.

 

[bucket]

But the damper opens when AC is set to Max to let water in. How will resealing the damper backside stop it.

The kick panel opening protrudes well into the plenum. Water runs down and around it, not through it.

 

[bucket]

If you remove the damper and kick panel assembly, you will see where and why it needs resealed.

 

[gotyourgoat]

If water is coming in around there, you need to remove the damper assembly and reseal the backside of it. It is open to the cowl drain, so it has it's own seal to keep water from coming in.

Curious as to what the appropriate sealer would be in this application. Guessing there are more than a few squares that have been fixed with silicone caulk but it seems wildly inappropriate.

 

[shinkle]

If you remove the damper and kick panel assembly, you will see where and why it needs resealed.

Ahh, I think I understand now. I have water coming in the driver side too but haven't removed the kickpanel to investigate. Pretty sure there is no AC damper on the driver side.

 

[shinkle]

If you remove the damper and kick panel assembly, you will see where and why it needs resealed.

Would a new damper do the trick? Like this link

Damper Assembly

 

[bucket]

Would a new damper do the trick? Like this link

Damper Assembly

There's just a basic sealer tape on the back side of the plastic kick panel. I don't remember exactly what type of sealer the factory used (foam/butyl/rubber/etc) and I also don't remember exactly what I used in it's place last time. It was probably just some basic strip caulk type stuff.

Your leak on the other side could be the windshield seal. The windshield seal could also be a portion of your leak on the passenger side.

 

[PrairieDrifter]

Use quality outdoor silicone or 3m strip caulk, I think the factory was a foam tape. I've had no issues with mine, I used silicone and live up North in the snow and a good bit of rain and haven't had any problems.

My windshield itself and it's seal isn't in great shape either. But no leaks other than my messed up A-pillar.

 

[AuroraGirl]

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at the right you can see the thingy

It is my opinion that indeed looks to be a foam tape that was compressed and most likely removal more than anything damages them. BUt if still originally installed, compression and contaminates probably abrasive enough to break the perimeter somewhere.
I would, personally, fix it with the use of butyl rubber but I dont know how it sits/howaccessible it is, if its not too bad to access, a sealant could be used like mentioned.. but I wouldnt want fumes in the interior, a curing chemical against the paint, or something that still has to stand up to cycling pressure debris dust etc.

Butyl rope can be purchased most likely at an auto store near you in the body isle, I got mine at advanced. 3m windshield butyl tape wrapped in a coil, its a LOT of butyl but its a great product because it retains its sealing and properties over time, conditions, etc for many years and still can be used again often. Its hwy its used to set windshields.
its also not at UV risk or Sun baking so bad as windshield

Its good to have. Use gloves(toxic if you handle too much) also california has found it to be cancerous but thats everything anyway

ALSO its called thumb grade sealer if you ever heard that term

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[WFO]

I used LMC's #10 in this diagram.
Looked like the original one, only the original one was wadded up and torn from before I bought the truck.
Stopped my leak just fine.

1975-91 Air Vent Components - Models with Air Conditioning

Shop from thousands of parts and accessories to help you restore, maintain, and customize your Chevrolet, GMC, Dodge or Ford truck or SUV. Keep 'em on the road with the right part, right price, right now.

www.lmctruck.com