Water leak in 81 sierra on both driver and passenger side

[2500sierra81]

i have an 81 gmc sierra 2500. during the winter it rains a lot and on both the driver and passenger side a small pool of water collects that seems to run down the sides from behind the dash. i can see the water becaus i have a rubebr cover over the carpet. i have investigated and can't seem to find the source of the leak. i've even hosed the truck down but no luck. I think it might be the pull air vents that are on both sides of the truck but the seals don't seem wet after it rains. any ideas?

 

[Swims350]

tons, vent windows, door seals, windsheild seal, cowl area plugged up down low letting water in thru the flaps or something. Got anythingon the cab outside like a visor or cab lights?

 

[bucket]

My '84 recently developed leaks exactly like you describe. I took the dash apart and found the source of the leakage on both sides, it's the window seal. It leaks even though the little drain holes under the rubber are nice and clear. I guess the rubber has just shrank and doesn't seal like it used to. I also resealed the kick panel vent, just in case... no dice.

 

[2500sierra81]

i took my dash off two days ago looking for any possible windhsield leaks and to fix some heating/AC problem and i didn't find any leaks. it wasn't the thoroughest inspection but i'm pretty sure its not a windshield leak. and as to swims350 comment i dont have any cab lights or anything on the outside.

also how hard is it to reseal the kick-panel vents?

 

[dhamp]

Mine does it too, but my didn't start til my dad had the windshield replace from some a-hole's muffler flying into it. Since I've been keeping it covered, I haven't bothered to look into it. It's in need of another windshield now, due to age. If the new gasket doesn't fix it at that time, I'll have to try the kick panel vents as well, I guess.

 

[bucket]

i took my dash off two days ago looking for any possible windhsield leaks and to fix some heating/AC problem and i didn't find any leaks. it wasn't the thoroughest inspection but i'm pretty sure its not a windshield leak. and as to swims350 comment i dont have any cab lights or anything on the outside.

also how hard is it to reseal the kick-panel vents?

I had the dash pad off and the glove box out. The leak wasn't obvious at all, but I could see traces where water had run in through the lower corners of the window rubber. It then drips off the firewall/pillar area, and just catches the lower edge of the dash itself, which then runs off the edge and down the kick panel.

It's not too hard to reseal the kick panels. I have AC, so there is only the vent on the passenger side. The rubber on the vent door itself was in good shape, but the foam insulation on the back of the kick panel was in bad shape. I just pulled it off and replaced it with some sticky-back foam tape from the hardware store. It was thicker than the original, but worked great. Getting the panel back in place was kind of a pain, my best advise is to start ALL of the mounting screws before tightening any of them.

 

[83K5guy]

My k5 leaks in the pasanger side like Andy said, looks like rubber weather stripping has sarnk. My 84 c10 always had water on the floor board after a rain and turned out the cowl had a bunch of trash (leaves and pine needles and what not). Hope this helps

 

[dhamp]

Mine always has water on the driver side, so I guess it shouldn't be the kick panel vent then.