Water leaking under dash when raining

[jklonowski]

I have a pretty good water drip under the dash on the driver's side by the fuse box. Trying to see if anyone has had the same problem before I tare apart the dash. Thanks guys for the help.
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[Altec]

Look inside the cowl. This is a common issue when trash collects in the cowl, and holds moisture. Mine rusted like this, but luck for me it rusted toward the engine bay.

[Hiluxxulih]

Ditto my 86 has rust holes big enough to pour golf balls into the cab .

[dmartin1]

check the windshield seal too,and for rust holes around the area....

note- mine actually had a small crack i the window from a pebble in the corner,and the water seeped through the glass,down behind the dash and to the floor by the fuse box.it had also ran in the crack of the glass to the metal of the cab where the glass sits and started to rust it.good thing i caught it.

[justpball]

windshield seal on mine leaked too

[blackbeaSSt]

im still chasing mine. although i think mine is the heater core on the passenger side

http://67-72chevytrucks.com/vboard/s...d.php?t=423766

[RandyP]

If it's rainwater/normal water, you have a leak from the outside. If it is sweet smelling like antifreeze, it's your heater core. Pretty darn easy to tell the difference there.

I've been lucky so far and had no leaks on a square, but had one in a early 80's El Camino once that drove me batty. I finally ended up gutting the interior, removing the front sheet metal and going crazy with seam sealer on the firewall after getting a new windshield urethaned in place (vs the butyl tape install).

[blackbeaSSt]

Originally Posted by RandyP

If it's rainwater/normal water, you have a leak from the outside. If it is sweet smelling like antifreeze, it's your heater core. Pretty darn easy to tell the difference there.

I've been lucky so far and had no leaks on a square, but had one in a early 80's El Camino once that drove me batty. I finally ended up gutting the interior, removing the front sheet metal and going crazy with seam sealer on the firewall after getting a new windshield urethaned in place (vs the butyl tape install).

but would the heater core leak with no outside water coming in like rain?

[RandyP]

If your heater core is bad and leaking, yes. Are you saying the housing is not sealed up correctly on the firewall and causing a leak, or your heater core is leaking? A leak on the passenger side in the floorboard is generally a good sign your heater core is doing something bad. But you should be able to smell the antifreeze pretty easy, assuming you actually have antifreeze in your cooling system and not just running straight water for some odd reason. You would also notice a drop in your coolant level, depending on the size of the leak.

[blackbeaSSt]

Originally Posted by RandyP

If your heater core is bad and leaking, yes. Are you saying the housing is not sealed up correctly on the firewall and causing a leak, or your heater core is leaking? A leak on the passenger side in the floorboard is generally a good sign your heater core is doing something bad. But you should be able to smell the antifreeze pretty easy, assuming you actually have antifreeze in your cooling system and not just running straight water for some odd reason. You would also notice a drop in your coolant level, depending on the size of the leak.

yeah i got a leak on the passenger side but only when it heavily rains or i am washing it. i haven't noticed the smell of antifreeze and in no way running straight water

[TDS-MN]

Windshield seal leaks on mine, bottom driver's side. Runs down to the same area as the Original Poster. Leak is much worse if I leave the kick-panel vent open accidentally. So far I have not bothered to try and solve this, though.