Greetings,
I've been battling a light to moderate water leak in my driver's side rear foot well and today discovered that it's coming from a nickel sized hole caused by rot near the driver's side hood hinge. I took it to my body shop and the guy refuses to touch it. He told me that to do it right would be extremely expensive and would require cutting through body panels. I understand that it may be difficult but part of it may have been that he doesn't want to bother. Regardless, I'm left to deal with this myself.

Has anyone else here ever had to deal with this? How do I remove the surface rust that is there? What should I use to patch up the hole that's there now? Tar? Expanding foam?

Thanks for your words of advice. I want to fix this as soon as possible so that no more moisture gets in the body panels.

Alex

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

Epoxy putty or epoxy liquid and cloth. You can get epoxy putty in the plumbing departments of most stores like Home Depot. Comes in a tube about an inch in diameter and about 8 inches long.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Kerry,
Thanks for the advice. What should I use to clear out the surface rust surrounding the hole?

Thanks.

Alex

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

Sandpaper and alcohol.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Pour alcohol on the panel and then sandpaper?

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

Are you sure you want to patch the holes? It seems over the years I have read about several "wet rear carpets" caused by the drains not being clear under the hood. A few leafs can cause water to not drain properly and overflow into the car. The water tracks below the front doors and ends up in the rear floor (with dry front floors). Seems to be a very common w123 problem with cars that are parked out side under trees. Could the rot area be surrounding the drain hole? You should be able to hose the two sides (near the hood hinges) out and they should drain prior to overflowing into the car.

Unfortunetely, any water that gets through the hole will end up in the rear foot well so I need to get it patched

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

I think I now understand what you mean by rot.
Not too much of that out on the west coast. At least not with 80's or newer MB's.

I had the same problem, but on the passenger side...rust/leaks near the water drain in the well of the hood hinge. I would try to fix this without patching the actual drain hole, although, not having seen your situation, I cant be sure that this can be done. Because of the very tough access in there, you will need to use a whole range of "surgical" tools (long screwdrivers, coat hangers, and various other things as these).


Here are my suggestions:

1. To remove rust, use naval jelly and wire brushes and various scraping tools (screwdrivers, etc.)..remove as much as you can.

2. Treat remaining rust with "rust treat"...there are various products at Auto Zone which convert rust to black....after treating, dry it with a hair drier (do this when your wife is not home!!!)

3. For patching, I used caulking compound for metal flashing...from Home Depot...it comes in a bright yellow caulking gun tube with bold black lettering, also with some red lettering, and the product name is "PROFESSIONAL"...it is black and specifically for sealing metal roof flashing. This works very well...stays flexible, sticks very well...I did my job about three years ago and its still intact. ALSO, to reinforce the patching materials, I used roof patching fabric...also from Home Depot, found near the shingles, tar paper and roof patch compound...cheap, comes in a roll about 8 inches wide. This is a loose see-through mesh which allows caulking compound to squeeze through...(dont use white fiberglass mesh for body work...caulking wont soak through). As you are patching, cut many small pieces of various sizes and lay them in as appropriate for the configuration of the work area....just like paper machet.

4. Before patching, clean intact painted area with soap and water and then paint thinner....you will want to apply the patch material to the effected area and extend it up and around the area onthe the intact painted area ...I used paint stirrers, popsicle sticks and various other things to spread the material.

5. Around the drain hole you might want to consider this...make some type of insert consisting of a tube with a flange to place into the hole and caulk under and on top. This will enable you to patch the area without patching over the drain. This must be absolutely water sealed and permanent, or you will have more leaks... I would try this: get a piece of copper flashing. Make a tube out of it of proper diameter and length to fit into drain hole. Form it by hammering it around a dowel. Solder the overlapped seam to seal it. then take another piece of copper flashing and cut a hole of the same size as the outside diameter of the tube. Set the tube into the hole and solder around it. Use a lot of flux to get good solder adherence.

6. Put black caulking materials around underside of tube & flange, and press into drain hole, then do patching as described above.

This should do it.

Good luck

__________________
1984 300TD Wagon, 407,800 mi (current daily driver)
1985 300DT Sedan, 330,000 mi (gone to that great autobahn in the sky)