I have recently found that the floor on the Driver's (left) side of my 420SEL is wet, and it seems to be water. The water seems to be coming from the front of the car, and I am presuming from the climate control system. I've been using the a/c a lot (it being 107F today in Tucson), and the car never has any condensation dripping from the bottom of the car after having the a/c on. I'm suspecting that a drain from the a/c is clogged and that is where the water is arising from. That's the best idea I've had. My questions are:
1) Does this sound right?
2) Has anyone had similar problems?
3) How do I fix it?

Appreciate all constructive input.

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Der Panzermann und Fraulein Fahrvergnuegen

1991 420SEL 201K "The Big Blue One"
1985 300DT 205K chassis/285K engine nee California emissions "Goldbug"
1983 300TDT 255K "The Womble"
1983 300 DT 214K "Sea Sprite"-Rear-ended a truck
1983 300SD 285K "The Donor" Gave his life so that others can live
1980 500SL Euro 105K "Der Panzer"

it is dripping from the expansion valve that is directly above the drivers feet. mercedes sells insulation to wrap it to prevent this

My take is that the hose that drains the condensate from the evaporator has rotted away. Just remove the carpeted panel from the transmission tunnel, and the hose will be apparent. There are two, one runs down each side. Replace it, and enjoy your dry feet.

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Tjohn

82 300 SD
77 450 SL (gone)

that is true, i forgot about that one too!

I found the hose! It was off of its rubber lined hole, and that was causing the leak. It looked really mucky inside, so I'm going to try to clean it, but thanks for the input!

__________________
Der Panzermann und Fraulein Fahrvergnuegen

1991 420SEL 201K "The Big Blue One"
1985 300DT 205K chassis/285K engine nee California emissions "Goldbug"
1983 300TDT 255K "The Womble"
1983 300 DT 214K "Sea Sprite"-Rear-ended a truck
1983 300SD 285K "The Donor" Gave his life so that others can live
1980 500SL Euro 105K "Der Panzer"

When I was getting water in the rear floor (Passenger side), I discovered that it was the antenna seal, where the water was coming in. Replaced the seal and no more water. Strange. I replaced it to keep water out of the trunk and it also stopped it from coming in the floor.

My case was definitely the hose coming from the evaporator core, but the Antenna seal would be another weak point. Before I figured it out, I was imagining all sorts of possibilities, like leaks being caused by taking the car through the car wash. I do get a little of fluid around the top of the trunk seal when it goes through the car wash, but not when the car gets washed with a hose. I think this may relate to the pressure of the drier fans flexing the trunk lid. I would guess in that regard that the sunroof is another weak point.

__________________
Der Panzermann und Fraulein Fahrvergnuegen

1991 420SEL 201K "The Big Blue One"
1985 300DT 205K chassis/285K engine nee California emissions "Goldbug"
1983 300TDT 255K "The Womble"
1983 300 DT 214K "Sea Sprite"-Rear-ended a truck
1983 300SD 285K "The Donor" Gave his life so that others can live
1980 500SL Euro 105K "Der Panzer"

Are you sure there are two of them? I easily found the one on the driver's side, adjacent to the transmission pan. While I had the car up, I looked for an output on the passenger side. I have not seen water dripping from the passenger side and could not find the outlet. If there were one in a mirror image position, it would drip almost directly onto the catalytic converter. I was doing this to avoid the disassembly if there was not a hose present. Could it have been eliminated on the 1991 420SEL and there is only one?

__________________
Der Panzermann und Fraulein Fahrvergnuegen

1991 420SEL 201K "The Big Blue One"
1985 300DT 205K chassis/285K engine nee California emissions "Goldbug"
1983 300TDT 255K "The Womble"
1983 300 DT 214K "Sea Sprite"-Rear-ended a truck
1983 300SD 285K "The Donor" Gave his life so that others can live
1980 500SL Euro 105K "Der Panzer"