water leaking inside thru cowl grate

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gashaller

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I have a 1971 dart swinger w/318 auto no a/c, I have the leak narrowed down to both lower corners of the windshield and water going in thru cowl grate. What are my avenues of repair? The water drips down from the sides, looking under driver side can't tell where water is coming from any help thankful LeRoy
 
Usually the cowl drains are packed full of leaves. Only way i know is to pull the fresh air box and heater box out and reach up in there clean out as much as you can and rinse with water. Unless of course you have rust issues.
 
Lots of threads on this. Common sources are the wiper pivots and the windshield gasket. If water from the cowl vent on the outside is coming into the cabin, it means one of two things- either the cowl is packed so full of leaves the water is running over the top of the lips around the cabin vents and into the vent boxes, or it was so full of leaves for so long the lower cowl rusted out and the water is coming through the holes. Because normally, there's a lip that's a couple inches tall around each cabin vent leading into the vent boxes that keeps water from the cowl from running into the vent box.

There's a wiper pivot repair how to here How To Fix Leaking Wiper Pivot Seals
 
There's a collar around the cowls fresh air openings so water has to pond in there a good inch or more deep before flowing over the collar and into the vent boxes. Then the vent boxes have 2 different type gaskets that could fail letting some of that water bleed between underside of cowl and vent boxes. That is unless there's a lot of rust through. The cowls drain openings are at each end so what goes out there runs down behind the dogleg end of the front fenders. A space between 2 bolts under that with whatever spacers were needed to get panel alignment are supposed to let the water and debris out to the ground. So if you do have a lot of leaves, pine needles, etc.., in the cowl, it can take some effort to flush it all completely out of the car.
Wiper pivots can leak water to the interior but not a LOT of water. For now I would assume the usual suspect, windshield gasket.
 
Check wiper pivot seals too

When I had windshield-area leaks in my Dart it was pretty much everything BUT the wiper pivot seals (though I replaced 'em anyway). Mine's a '67 post, and the 68-up windshield gaskets seem to fit a little loose, which was 90% of my problem.
Lots of good advice here, be careful cleaning out the cowl vents...sharp edges alert!! I wrapped some duct tape around my wrist so I didn't slice a vein.
Also, don't overlook random holes either in or near the cowling (mine was leaking around the screw that held the F tee for the windshield washers), also look for holes behind the kick panels (had one of them too).
 
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I made a "U" piece out of unglued 1" PVC pipe that I duct taped to the end of my shop vac and I reached in thru the two under-dash vents (non-AC car). Then I vacuumed full circle around the cowl opening to get out all of the pine needles that collected there. If you also have rust holes, then this will show up inside the car on the flooring. First guess is usually the wiper pivot shaft seals though. But if you can see junk inside the cowl, you should definitely vacuum it out too.
 
If water is coming in a screw hole or seam, or even small rust holes, 3M rope sealant works great. O'Reilly's has it.
 
Compressed air, leaf blower, shop vac at all available opening.
Suck blow, suck blow, blow suck, blow suck, suck suck suck, blow blow blow.
Unless you pull the heater box and can reach up from inside the car.
Not fun.
I'm not above cutting a round hole in the front of the cowl if necessary and then using a body plug there.
Done it on later cars that had one side with a hole in it anyway for some stupid vacuum control thing there.
IF you manage to get it cleaned. spray Rustolem Rusty metal primer all up in there.
Cowls are rust time bombs.
 
I’ve been chasing my tail trying to find the source of leaks in the front and rear of my 70 Dart Swinger. I replaced the wiper pivots but still have a leak or two in the front. I cleaned the cowl drains as best as I could. Based on this thread, I’m assuming it’s the windshield seal.

It looks like the rear is leaking around the window seal and where the old vinyl trim screws are.

Does anyone recommend any particular window seal product/company? I know there are a lot of cheap products out there so I’m looking to buy something others had success with. Thanks
 
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