Hi All-

New user here, new 300SD owner. I've had it for a few months, during which time I've been reading feverishly. Diving into the top triage issues, and while I'm waiting for the valve wrenches, I'm looking into the leaking trunk. I've done a lot of looking both here and in other sites, but can't seem to find the answer to what seems like a silly question. Both rear windshield and tail lights are leaking. Starting with the lights first.

Using this as a guide, I am trying to replace the two seals per side. I've found (MB p/n A 126 826 00 91) the thicker seal that seals the main body to the chassis. What I can't find mentioned anywhere is the thinner "bead"-type seal that sits between the lens and the body. It's thin, maybe 1/8" (~3mm) and of course runs the circumference of the tail light lens itself. Is it #17 on the drawing above? If so, what is the p/n and where can I get it? It looks like #11 is the thicker gasket which has been easy to find if not stomach.

Also, since I have you, some of the posts that receive the screw in the lens itself are brittle and have broken off. 3 of the 4 are missing chunks, which I have. Can I carefully epoxy these back in place if I don't get any in the threads?

Thanks for any input!

Welcome to the forum! There are lots of 126 enthusiasts on here that have extensive knowledge to share. I know of several in the Bay Area.

I know that body tends to rust badly under the back window and you may have trouble brewing under the seal for the back glass. The glass isn't like modern cars that is urethane bonded to the frame. These windows were set in a rubber gasket, shaped like an H, the glass in the top of the H and the body pinch weld in the bottom of the H. Water gets under the gasket and you know what happens next.

These were built before hot dip galvanizing was a thing so these bodies rely on paint and sealant to prevent rust.

I had to jump into your post and remove the link to a competitor part site since we don't allow that here per the http://www.peachparts.com/shopforum/diesel-discussion/295403-thread-rules-please-read-before-posting.html.

The forum sponsor does carry this part, put the MB part number in the search box at the top of every forum page.

Sounds like you saved one from the crusher, get some pictures up for us to see!

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Not on a Mercedes but I have sealed tail light and other light lenses like the side lights with Silicon Sealant. I normally use black but they used to have clear.

I also had to remove my Rear Window (I had 2 holes under the rubber) due to rust under the seal. That was over 8 years ago and since that time it has stared rusting again.

I also had the area behind the rear wheel rust through in to the trunk and water got in that way.

On the W123 on the outside of the trunk seal is a channel that needs to be kept clear so that the Water runs out of it.

__________________
84 300D, 82 Volvo 244Gl Diesel

Thank you for the quick approval and link correction. Apologies. Certainly not trying to bypass Pelican--they were great to me on several Mini projects.

Regarding the seal, the part number above is NOT the one I want to replace. I mean I do, but the one I'm trying to find is on the other side of that plastic reflector box (certainly not what it's called but hopefully clear). It's the much smaller diameter seal that seals the lens itself to that plastic box. The larger seal seals the entire assembly to the car. I'm attaching a pic, but not sure I have permissions with (now) 2 posts.

Fancy picture drawing (the king of quality you can expect from CantComplain!) attached.

Attached Thumbnails

 

URO has the tail light gaskets and is in the process of adding them to this site. Perhaps contact user URO and ask when the addition will be complete and whether there are other options.

I've also sealed with tube sealant. I used this stuff which was recommended by a retired bodyman.
(3m auto bedding & glazing compound black - 08509)

It is black and doesn't harden making it easier to remove if needed than silicone. I don't know how long it will last as it's only been on for a year. There is enough in the tube for more than 2 126 cars.

You can take a small pick and GENTLY probe under the rear windshield gasket to find the leaks (holes). Check with a small tote the note car lot and find out who they use for glass work. You want the old guy that knows these cars. I can get an install done for $60 in TN but that only includes the install because the glass was already out.

The c-pillar trim is removed 1st and the window heating element is disconnected from the body. The 1st glass man didn't know what he was doing and screwed that part up.
Be ready with tarps to keep the water out because you'll need to fix the hole and use a rust paint.

I've bought Kayme 6 Layers Car Cover Waterproof All from Amazon at the recommendation of someone on this forum and they work well for short term. Long term, tarps and impermeable covers cause rust.

__________________
85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.