Leak under dash

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rwljpl

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I have a leak - water is ending up on the floor on the drivers side. I thought it was coming from the vent window or door seal. I changed out the seals only to find out water is actually coming down though the dash in the corner. It’s dripping under the far left of the dash. Any ideas on what to do? I’m guessing water is coming down through the cowl. Could I have a clogged drain plug? I haven’t messed around with it much but any ideas? Anybody had this issue and solved it?
 

Mofarmer

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Mark
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C10
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I have a leak - water is ending up on the floor on the drivers side. I thought it was coming from the vent window or door seal. I changed out the seals only to find out water is actually coming down though the dash in the corner. It’s dripping under the far left of the dash. Any ideas on what to do? I’m guessing water is coming down through the cowl. Could I have a clogged drain plug? I haven’t messed around with it much but any ideas? Anybody had this issue and solved it?
I just had the same issue with my 86 c10. My suggestion would be to remove the cowl and look under it. These trucks are notorious for rusting in this area, I was very fortunate to not have any rust, there is a seam in the bottom of the cowl where the water drains to the fender drains that is sealed with factory seam sealer. My seam sealer was cracking and coming loose and letting the water leak into the cab. I cleaned the cowl and resealed with SEM sem sealer and I believe the leak is fixed.
 

rwljpl

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Thanks. When it stops raining I’ll try this.
 

louu

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Yup, I was gona say the same thing as mofarmer. I got some 3m seam sealer at my local auto parts store. Expect to pay a lot for it. The 3m stuff was almost 30 bucks
 

Curt

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A lot of debris can gather up in there.Leaves,sticks,and dirt.Hopefully it’s just not draining right and needs cleaned out.
 

sirweesarunch

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This is the point of all kinds of sheet metal damage , floors , kick , rocker etc etc. The cowl seal fails , rusts out and sends water careening down the firewall behind the insulation and under the carpet. I spent probably a 100 hours fixing all of the above damage caused by $3 .00 of seam seal that failed in that critical area. Squares are known for this flaw and rusted roofs where those drip rails let water into the inner roof. Fix the cowl first and save your square from the crusher.


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