Wet Passenger Floor - 07 YukonXL with sunroof

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Wolfbraid

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Yup, I've searched Just looking for more guidance.

So Typically a wet pass floor is one of a few things.

I was able to get to the drain on the firewall from below the truck.
The drain comes straight out of the firewall(no 90 degree elbow in place)
I fished a pipe cleaner into it about 3-4 inches? with no restriction, also came back clean and dry.
When the blower is running I can feel air blowing out of the drain pipe.

Today when I left work Sunny day, the floor was dry to the touch, by the time I got home 20 minutes later
there was a small moist area near the low point(near the bottom of the kick panel)

I pulled up the carpet a bit in the foot well, and it's pretty damp, it doesn't seem it's been getting wet for long, as all the carpet and padding has clean water, no mold etc. The padding heading up the firewall is damp as well.

Other than the drain is there anywhere else that would leak water, how easily can I access the interior side of the drain pipe?
 

Big Mama

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Could be the heater core itself. Have you had to add fluid lately? Next time it’s damp see if it smells like antifreeze or at least engine water. Sounds like the culprit especially since it got wet after driving.
 
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Wolfbraid

Wolfbraid

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Could be the heater core itself. Have you had to add fluid lately? Next time it’s damp see if it smells like antifreeze or at least engine water. Sounds like the culprit especially since it got wet after driving.

Its Definitely water, tastes like water too ;) as much as it sucks I'm going to run a couple days with no A/C and also pull the bottom cover off the blower assembly thing(sorry forgot the name) and going to see what I can from there.

How deep do people clean into the drain hole, I'll get stiffer pipe cleaners if needed, but since air was blowing out of the hole I figured it was clear.

Does anyone know how essential the 90 degree drain pipe is coming out of the firewall(mine is missing) I can't imagine it is essential to drainage, but I'll grab one asap anyway, was just curious.
 

Big Mama

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If it’s the pipe I’m thinking of it drains condensation out of the truck. What happens when you turn the heater on? That’s an easy way to test for heater core. Put a towel on the floor and turn on the heater with the truck running at temp.
 
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Wolfbraid

Wolfbraid

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Thank you for the suggestions.. I found the culprit, thank goodness for small miracles, I don't need a large job yet on this new to us vehicle.
apparently when someone reinstalled the Blower cover/Sound cover they missed the factory hole and made their own. So I'll let it dry and seal it up, I'm guessing epoxy or something like that, unless someone has another suggestion.

Picture of the water flowing out onto my dirty mirror finish trowel.

IMG_20180907_162250792.jpg
 

kbuskill

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Thank you for the suggestions.. I found the culprit, thank goodness for small miracles, I don't need a large job yet on this new to us vehicle.
apparently when someone reinstalled the Blower cover/Sound cover they missed the factory hole and made their own. So I'll let it dry and seal it up, I'm guessing epoxy or something like that, unless someone has another suggestion.

Picture of the water flowing out onto my dirty mirror finish trowel.

View attachment 206852

My guess is RTV would work fine.
 
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Wolfbraid

Wolfbraid

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Well it's wet again... not coming from the same spot... time to start digging.

how important is the L shaped elbow that comes out of the firewall and drains? I haven't found a replacement for that yet.

Well part is
15-34717

apparently I've read a couple places that without it water can drip backwards through the firewall..seems probable.. I'll grab one or a spark plug boot works as well.
 
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Big Mama

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Did you look on Rock Auto? You’re correct the drain is important to avoid mold and potentially rust
 
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