I have to fix this problem but I wanted some experienced help.

I have experienced wet carpet and wet floorboards for several months now... at first I thought it could be the heater core so I disconnected it and just ran the heater hoses looped from the water pump to the to of the intake. Still I find my carpet wet in both the driver's and passenger's floorboards under my floor mats. Where do you think the water could be coming from? Windshield seal or possibly something in the cowl?

Thanks,
Jody K.

 

I suspect the area at the base of your windshield is rusted out underneath the stainless trim and sealant...typical of 64-67 cars.

 

Yep. It's the windshield channel. I'd recommend fixing it the proper way, which will involve removing the windshield, wipers, and dash pad (I'd recommend removing it due to heat from welding the channel). At that point, you'll have to assess how bad the rust is and whether it goes around the entire channel or it's just the section nearest the cowl.

 

Unfortunately it's typical of all the 64-72 cars. Patch panels are available for both the 64-67 cars and the 68-72 cars now. Do not think you can fix this by simply slathering on silicone. All you'll do is trap moisture and accelerate the rusting process.

By the way, if the wetness is on both sides, it's unlikely to be the heater core. The heater core is on the passenger side and would usually only leak on that side. In addition, you'll smell the sweet antifreeze smell.

 

another possibility (although the window channel as others have mentioned it is pretty likely)

Another posibility would be water coming in through your kickpanel side vents.. Originaly these were sealed with this thick goopy stuff- but after pulling them in & out once or twice they are no longer sealed.. and when it rains or the car is washed, water runs down inside the cowl plenum, hits the top of the kick panel vent doors inside the plenum space where they stick in, and water runs inside the car.

Also- if there is a bunch of leaves & stuff clogging up the drain holes at the bottom of those side areas, so its possible for them to fill up with water until it start spilling over into the car through the kick panels.

Pull your kick panels and take a look inside to see if they are filled with junk clogging up the drains or not.

 

And the above post also describes why fenders tend to rust at the bottom1
Friend pulled the front clip off a '72 BB Chevelle he bought last year, and could've filled a 5 gal. bucket with the crap in there!

 

First off I assume your car is parked outdoors? Rain getting in? There can be more than a few problems here. I had experienced the same problems but thankfully after going through much of the causes I pin pointed it to the door weather stripping. If the seal is not very good towards the lower bottom of the doors then water will work its way through the kick panels and sill plates. Also you won't know much til that windsheild is pulled out but if you can see through the lower coners of the windsheild for any rust bubbles on the dash panel then that will likely be the cause and some work required. Hope you find the problem.

 

just finished 65 cutlass it to suffered wet floor syndrome. my problem was bad door gasket seal (new gaskets)where the roof rail & door gasket merge at the vent posts.water migrated down and the door sills@the corners of the kick panels into floor pans pretty bad leak... alls i can figure is the doors are out of aligment and not compressing the door gasket properly at the vent rail corners.