My trunk leaks/got a leak in me boot - PeachParts Mercedes-Benz Forum

cmac2012 · #1 11-18-2005, 04:10 AM

My '81 300SD, 126 of course, has a leaky trunk. Can't tell exactly how the water's getting in. The back window and rubber could use replacing but this rig's not worth that sort of investment, not yet anyway, so I carefully applied Sikaflex to both sides of the rubber. When I open the trunk, water has condensed on the underside of the trunk lid, unless it's somehow leaking directly onto that surface, under the weather stripping.

Any experience with this?

hdexpert · #2 11-18-2005, 07:50 AM

I also have an 81 300SD which had a VERY wet trunk when I bought it. Now keep in mind, this is my first older Mercedes deisel and I knew nothing of the chronic ailments of this car let alone the existence of this forum! So, first I installed a new real window seal, it helped a little. After that, I climbed into the trunk with a flashlight and had the wife hose down various parts of the trunk area. Low and behold, very leaky tail light seals! So, I removed both lights, discarded all old seals and cleaned all surfaces. Then came the black silicone sealant! Keep in mind, this car is my driver, I wouldn't do this to a nice car. Well the sealant worked wonders, my trunk is now dry as can be!!!!

cmac2012 · #3 11-19-2005, 03:46 AM

You sir, are a gentleman and a schoolbus, uhh... I mean, scholar. I was thinking about trying the getting in the trunk for a good hosing routine myself. I'll check out the tail-light seals first. Makes sense.

hdexpert · #4 11-19-2005, 08:06 AM

Cmac, glad to pass along the small amount of Mercedes knowledge I have accumulated so far! Let me know what the outcome is.

andmoon · #5 11-19-2005, 10:02 AM

Don't forget the taillights has 2 seals. 1 between the light assembly and the body and another between the lens and the black plastic. I know because I had to do them twice.

E5004ME · #6 11-19-2005, 01:37 PM

We had a puddle in the well on the passenger side and I found that the drain hose from the gas flap had plugged. Reamed it out and it appears the problem is gone. It's easy to check, open the gas door and pour a cup of water to see if the drain works.

cmac2012 · #7 11-19-2005, 01:41 PM

Excellent advice. I'll post results on this thread before too long.

I use my Benz for work a lot and I like the big trunk for tools. Don't like getting them wet, though.

cmac2012 · #8 11-24-2005, 09:45 AM

I tried hosing the lighting area copiously with some paper towels inside to indicate if water had flowed. Doesn't seem to be it.

One thing I've noticed, whenever I open the trunk (during the wet months) there's a lot of condensate on the underside of the trunk lid. This will be happening even if the rest of the trunk doesn't seemt that wet. In the bottom edge of the trunk lid is a small opening you can sorta get your fingers into and it usually has standing water. This is probably some of the condensate that just runs down into the space.

I'm also thinking it might be indication that water is leaking in via the holes that attach the "300 SD" and "DIESEL" and 3 pointed star insignia, though I might be grasping at anything here.

Palangi · #9 11-24-2005, 11:13 AM

Take a close look at the trunk seal. One of mine has a crease in it. Kind of looks like some previous owner may have routed a CB antenna cable or something diagonally across the seal. I am going to have to replace the seal in order to cure the wet trunk problem. This one also has dampness and evidence of rust on the bottom of the trunk lid.

hdexpert · #10 11-24-2005, 11:38 AM

Cmac, apply a thin film of petrolium jelly to the trunk seal and close it.Now open the trunk and see if the jelly transfered to the lid. A neat little trick!

t walgamuth · #11 11-24-2005, 09:19 PM

climbing in the trunk with your wife hosing down the back end of the car.... just be sure you havent pissed her off anytime in the last year or so.

tom w

haasman · #12 11-24-2005, 10:48 PM

I had an 82 300SD and it leaked into the trunk. It was the rear window molding. I did a lot of searching for a good price and found it for about $65 several years ago.

Good rule of thumb: if you lift up the windshild rubber and it doesn't snap back ... it should be replaced soon...by how fast the rubber returns is a great gauge to how old the rubber is.

If you decide to do it, be very careful of the rear window defogger wires going through the rubber window molding on each side. The electrical connections are VERY easily broken, very easily .... don't ask me how I know this.

The rear tailights housing also are known to leak. Also check in the trunk wells for missing plugs and for junk accumulated in the sunroof drains.

Haasman

cmac2012 · #13 11-26-2005, 03:57 AM

Quote:

Originally Posted by Palangi

Take a close look at the trunk seal. One of mine has a crease in it. Kind of looks like some previous owner may have routed a CB antenna cable or something diagonally across the seal. I am going to have to replace the seal in order to cure the wet trunk problem. This one also has dampness and evidence of rust on the bottom of the trunk lid.

My trunk seal looks a bit rough. When I got it, part of the metal rail the seal is attached to had rusted out. I fashioned a piece of thin steel to bridge the gap and attached it with mucho JB Weld. It's hard to figure the trunk seal. Even if it's not perfect, the little channel around it ought to drain out most all of the water. The trunk on my Bimmer is almost loose around the seal -- doesn't seem to close super tight but it hardly leaks at all. Just a few drops in one spot.

I went to see a 300SD that looked real good in the Craigslist picture. Looked good up close too but had many little bugs. The owner said he was a mechanic.... well, maybe, hard to say. His trunk was pretty wet also. He'd replaced the trunk seal and there must be some tricks to it he didn't know about. At the two sharpest turns, the stuff kinda puckered out. Definitely not the way it comes from the factory.

Not to be a wet blanket, just a word of caution.

cmac2012 · #14 11-26-2005, 03:58 AM

Quote:

Originally Posted by hdexpert

Cmac, apply a thin film of petrolium jelly to the trunk seal and close it.Now open the trunk and see if the jelly transfered to the lid. A neat little trick!

THAT is a neat li'l trick. I'll try it.

cmac2012 · #15 11-26-2005, 04:00 AM

Quote:

Originally Posted by t walgamuth

climbing in the trunk with your wife hosing down the back end of the car.... just be sure you havent pissed her off anytime in the last year or so.

tom w

HONEY!! C'mon baby... no really, I like your hair like that. I was just trying to make you laugh. No, really I was. And that dress you wore to the party the other night? Smashing! Really smashing! Now come on sweetheart, this was funny for the first 5 minutes...

Honey? HONEY!!