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

cmac2012 · #1 11-18-2005, 05:10 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, 08:50 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, 04:46 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, 09:06 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, 11:02 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, 02:37 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.

haasman · #7 11-24-2005, 11:48 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 · #8 11-28-2005, 05:36 PM

Quote:

Originally Posted by haasman

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

You managed to replace the rear window molding yourself? How tough was that? I was under the impression that it was one of those tasks that required special knowledge and tools to pull off.

My rear window defroster only works on the top half. Oh man, if I could somehow stop the leak and get the entire window to defrost/defog, THAT would be a good day.

haasman · #9 11-28-2005, 10:15 PM

It isn't really that hard if you know how to do it.

If your rear window is only defogging on the upper half of it, I beleive that means that the connections are broken. You might be able to repair that using a liquid solder but .... very iffy.

The key to the rear window molding is handling the aluminum trim carefully and not pulling the wires off the window sides.

Installing isn't hard if you know how to install auto glass using a 1/4 nylon rope, lots of patience and silicone spray.

Haasman

t walgamuth · #10 11-29-2005, 05:47 AM

luck cauliking tired windshield front and back with black 100% silicone. clean joint with alcohol and caulk a small bead on the joint between the glass and rubber. i sometimes cut a small part of the edge of the rubber off about 1/8" and form a groove for the silicone.

i 've been doing it for about 20 years first time with my 51 caddy. sometimes i have had to do it after a new gasket is installed to seal it up.

tom w

cmac2012 · #11 11-29-2005, 05:57 AM

Quote:

Originally Posted by t walgamuth

luck cauliking tired windshield front and back with black 100% silicone. clean joint with alcohol and caulk a small bead on the joint between the glass and rubber. i sometimes cut a small part of the edge of the rubber off about 1/8" and form a groove for the silicone.

i 've been doing it for about 20 years first time with my 51 caddy. sometimes i have had to do it after a new gasket is installed to seal it up.

tom w

I tried that already with black Sikaflex but it didn't seem to work. Now I see some of the Sika is degrading in the UV.

I was thinking silcone might be better. This car would be just fine w/ a slightly big and crude looking silicone enhanced window bushing.

My dad used silicone once on a mid 70s Mazda -- worked fine.

I'll try it. I discovered a leak today after a rain in the trunk right under the rear window. Don't know why I couldn't find that before.

cmac2012 · #12 11-29-2005, 05:51 AM

Oh man, that's what I was afraid of... I don't know about the 1/4 inch rope method or even lots of patience.

If only the car was closer to a cherry, I'd buy a new rear window and have it done professional-like. I could just see me breaking the wire to the part of the window that does defrost... and then not being able to get it back in.

Hate to be so pessimistic...

250 Coupe · #13 12-02-2005, 12:45 AM

Quote:

Originally Posted by haasman

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.Haasman

Er... Does this mean the entire window rattling in the opening isn't a good thing?

It goes thumpa thumpa while I'm scrubbing it on the inside.

Michael

250 Coupe · #14 12-02-2005, 12:53 AM

I took my 1971 250C to a glass shop and requested a quote for new glass and rubber. He pretty much refused to give me a quote but did offer to try to seal it for me.

He gave me a plastic tool and sent me home with instructions to clean the gap between glass and rubber with a blast of water from a garden hose.

When I returned, he used an industrial caulking gun loaded with bedding compound to run a bead between glass and rubber. He shoved the nozzle well under the rubber and filled it up. Afterward, he hosed it down with foaming glass cleaner and wiped away the excess. When he was done you couldn't tell he'd done it, it came so clean. I figured if I tried it I'd have compound on the roof, hood and me!

He refused payment as he didn't "want to be married to the job".

Hasn't leaked since.

Michael

cmac2012 · #15 12-03-2005, 03:59 AM

Uhh.. lemme see, it would cost me how much to get up to Des Moines?

(Long time Seattle - former - resident here)

Damn, I hope you gave him a six-pack or something. That's some wild stuff.

Any idea what the bedding compound was?