After carefully patching up under the driver's side hood hinge, from the inside and the outside, it appears as if that area is staying dry but I'm still getting a lake in the rear footwell after it rains!

If it was the a/c evaporator hose that individuals are talking about then the water wouldn't be associated with rain, correct?

I've also heard about the window seals...are we talking about the weather stripping around the door or something altogether different?

Seriously frustrated. My wife is a Pisces, I just got done breaking my back putting gutters up on the house to dry up my basement, and now this....iIm not a man, I'm a full-time water manager!

From what you describe, I had a similar problem. I looked for a rain leak for a while, but it turned out to be the A/C drain. Thanks to others who have described this fix before I was able to make the repair.
Remove the passenger kick panel and the console panel. Reach up on top of the transmission hump, there is a white foam rubber hose coming down, remove it and replace it. When the hose is deteriorated , water tracks down along the tranmission hump covering and emerges along the floor ending up in the rear passenger foot well. Remove the thick foam rubber insulation floor pads. They will be filled with water. They take a LONG time to dry. Good luck.

Steve

W123/W126 chassis cars and ealier have front and rear windshields retained by a large black rubber gasket, called a "lace-in" type. These get old and hard and shrink, and leak under the rubber at the bottom, channelinn water down the dash or rear package shelf and down the the floor.

The water ends up in the rear footwell since it is the lowest part of the floor pan, and on the W123 sits in some depressions around the seat attachement points for the front seat. Will rust out the floor if not stopped!

Sunroof drains will also get plugged and dribble water down, and the metal nipples on the sunroof can rust off. This usually drips watter out of the headliner or window trim, though, not just out through the rear carpet.

If the gaskets on the front and rear windows are not longer pliable and won't snap back when you pick up the edge with your fingernail, replace them. When they get really hard, the windows will rattle and creak, and the aluminum trim will come out of the channel, too.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

I have seen a tech bulletin title which mentioned some change to the frame under the rear window I believe.. might be good to check the specifics before starting the fix... maybe they figured out how to fix it....

Been there done that. Fixed the #$^%($$ gaping hole under the hood hinge which allowed a deluge of water to come in. I pulled all carpet and driver's side seat out and directed water to the corner of the hood to be sure, then the fresh air intake, then the window gasket....no leaks detected.

Then I moved to the side of the car and directed water to the door edges, along the base of the window, and then the space between drivers' front and rear doors. After waiting for a few minutes I did then notice that there was a tiny trickle coming out near the "hump" that supports the front 2 bolts of the seat...there was water seemingly oozing from the inner sill just behind the "tunnel" where the vacuum lines, etc. exit.

Upon closer inspection and some careful screwdriver work, I found the metal was rusted through the sill and also through the floor. To give you an idea of location: go underneath the running board and locate a rubber drain which is sort of streamlined, pointing towards the rear of the car. Pull it. This is apparently where water was collecting, not draining, and then slowly rusting out the sill and floor.

So: NOT sunroof, NOT front window, NOT window seal, NOT A/C evaporator hose, NOT hood/hinge drain. A NEW AND EXCITING PLACE TO FIND RUST!!!! I almost peed on myself I was so happy (LOL) to find my car insists on being different.

I've repaired with mesh and fiberglas (it was a relatively small area) and because it's like the freakin' Pacific Northwest here I'm sure it'll pour down rain in the next couple of hours so I can check the viability of my repair.

Ok, love my car, love everything about it, thinking about being my car for Halloween but I'm getting majorly sick of having to repair rust. My car doesn't have to be a perfect beauty but I'd rather do things to improve the performance than just tread water, literally. I suppose I should have purchased from California or something.