Trunk leak :( - PeachParts Mercedes-Benz Forum

Silber Adler · #1 11-21-2012, 08:09 PM

I was loading my trunk this morning and saw water in one corner. Passenger side. I think it is coming from around the rear window.

Any hints? Thanks.

Brian Carlton · #2 11-21-2012, 09:42 PM

It is.

Unfortunately, you've got a big job ahead of you.

First, go to the dealer and get an OE rear window gasket.

Then, read up on how to cut the existing gasket and remove the rear window glass.

Then, clean up the channel with a wire brush and hit it with POR-15.

Then, you have a decision to make. Installing it by yourself is quite a task and dangerous. Installing it with a helper is better but also risky if you have not done it.

Finding a shop to do it who has the expertise............PRICELESS.

BTW, priceless costs about $175. but it includes the best available sealant.

No more leaks for the next 20 years.

Stretch · #3 11-22-2012, 04:49 AM

Other places that might be leaking on that side of the car are

1) the boot / trunk seal - especially if it has rusty metal in the corner in the gutter and the outer wing joins

2) the rubber seal that goes over the fuel tank filler pipe also leaks => with lots of rain it pours down the side of the car into the fuel tank filler recess and it should then go down the little overflow pipe that then comes out just in front of the rear right hand side axle. (This isn't likely to make a leak like that shown in your picture though - but I thought you might like to know)

3) (Also not related to the obvious leak in your picture but for future reference) the rear light clusters can also leak as can the boot / trunk lock mechanisms as can the trim strip that runs along the lower edge of the boot / trunk (this one makes an irritating drip inside the boot every time you open it)

EDIT - I think it is worthwhile pointing out that on the whole W123 rear windscreens don't seem to rot like the W126 ones - if it turns out to be a leaking windscreen rubber I reckon you've got a better chance of it not being totally rotten - so good luck.

charmalu · #4 11-22-2012, 05:17 AM

I have removed a few of the rear windows, my own and the junk yard.

Best to remove the rear seat, and remove the 17mm bolt that hold the seat belt to the floor.
Remove the "C" pillar panel, and pull the belt through the hole.
Remove the Phillips screw on each side for the electrical connection. careful not to bent the metal or you will break the connection on the glass.
using a razor blade knife, cut the gasket on the inside, up one side, across the top and down the other side. peal off the rubber strip.
The headliner fits under the gasket, careful not to cut too high.
Then gently push the glass out from along the top working from one side across the other. careful not to tweek the glass.
From the out side pull it back, up and out.

You will generally find rust a little, or a lot. I removed a window from an 85 300CD, and there was no metal left all along the bottom. no rust showed from the out side.

This morning I was greeted with water leaking in the trunk on the 240 for the first time, so I`ll be doing this when I get back from this trip.

Probably give Phill a call on Friday and order the MB Gasket.

Here is a DIY Article.
PeachPartsWiki: Rear Window Seal Replacement

Charlie

cho · #5 11-22-2012, 12:48 PM

Quote:

Originally Posted by Brian Carlton

Finding a shop to do it who has the expertise............PRICELESS.

my friend broke 2 on SEC.... then he went to a shop...

.

alamostation · #6 11-22-2012, 10:14 PM

It is amazing how little a hole it takes to let a lot of water into trunk.

Guderian got a trunk full of water every time it rained. I finally found a dime sized rust hole near the bottom of the rear window. A fingernail sized portion was visible outside the gasket. I dug out the dirt and rust from under the gasket and filled in the hole with 3M window sealant.

Problem solved.

Brian Carlton · #7 11-22-2012, 10:45 PM

Quote:

Originally Posted by cho

my friend broke 2 on SEC.... then he went to a shop...

.

I had the same fear and the cost of a replacement window would greatly exceed any savings by attempting to do it without professional help.

Furthermore, the new sealant that these fellows use is far superior to anything that I've seen for a retail customer to purchase.

Even the removal of the window is more difficult than Charlie indicates. It is very easy to tweak the aluminum trim during the removal process and, if you do, it won't properly go back into the new gasket.

You must remove it yourself, however, to properly treat the sill with POR-15. Be completely foolish to blindly bring it to a shop for an R & R. Furthermore, they won't procure a new OE gasket.........for certain.

Silber Adler · #8 11-22-2012, 11:16 PM

I have lifted up the aluminum channel and found a small pucker in the molding between the metal and the rubber almost right above the wet spot. I have drilled a couple of holes in the sheet metal inside half expecting water to come out and didn't get any.

I am going to attempt a repair before I take out the glass. I know how heavy and relatively how fragile they are.

charmalu · #9 11-23-2012, 03:08 PM

Quote:

Originally Posted by Brian Carlton

I had the same fear and the cost of a replacement window would greatly exceed any savings by attempting to do it without professional help.

Furthermore, the new sealant that these fellows use is far superior to anything that I've seen for a retail customer to purchase.

Even the removal of the window is more difficult than Charlie indicates. It is very easy to tweak the aluminum trim during the removal process and, if you do, it won't properly go back into the new gasket.

You must remove it yourself, however, to properly treat the sill with POR-15. Be completely foolish to blindly bring it to a shop for an R & R. Furthermore, they won't procure a new OE gasket.........for certain.

Yes, it is easy to tweak the aluminum trim, and if it gets bent almost impossible to straighten it out. what I was mentioning was removing the window with the gasket and trim still on the window. I do it this way in the yards so the rubber protects the glass edge while transporting it.

I had an old glass guy that had done hundreds of MB`s over the years explain how he removes the trim. slide the piece back from that covers the sections at the top. gently lift the trim enough to get a cord under it. pull it through so you have both ends. then pull the cord while holding the trim down from curling. I tried this a couple times and seemed to work ok, but still the danger of tweaking it.

I`ll be replacing the 240`s glass very soon, after I order the OM gasket from Phill. and will post how I get the trim off. thinking just cutting along the sides of the trim with a razor might be enough to release it with the window out and on some saw horses. we`ll see.
I will practice on a few in the yards to refresh things.

Charlie

Silber Adler · #10 11-23-2012, 03:39 PM

Since I am not seeing moisture inside the car anywhere except the trunk I am going with a repair rather than a replacement.

I took out the aluminum trim. Finding a pucker on the inner seal a second layer, under the outside seal. I chose to use a liquid rubber product called three bond. It is the recommended product to put on crankcase halves on yamaha 2 strokes. It once it cures it stays very soft and is durable to fuel and solvents.

I pried up the layers and dried the inside with cotton swabs. Using a solvent to remove any oils.

Three Bond is easy to remove. if it doesnt work, nothing lost.

I used some silicone lubricant on the rubber when it came time to put the metal expander back in.

I have some Goop and was considering using it that is why I have the duct tape over the paint.

Stretch · #11 11-24-2012, 08:05 AM

I'll be interested to see (= read!) how you get on with this fix. When I removed the windscreens on my car I was amazed to see so much muck had found its way between the glass and the seal. The rubber itself could probably have "done another trip" if it wasn't for the path way of muck that was allowing the water into the car.

Will this stuff stick and seal to muck or seal the muck; and stop the water from getting in?

Brian Carlton · #12 11-24-2012, 09:32 AM

Quote:

Originally Posted by Army

Will this stuff stick and seal to muck or seal the muck; and stop the water from getting in?

Depending on the deterioration beneath the gasket, the sealant might be acceptable as a temporary fix. The decomposition of the steel won't stop, however, and the problem is postponed into the future. The future might be two years or ten years down the road..............nobody knows for sure.

Silber Adler · #13 11-24-2012, 10:26 AM

Yep guys the seal is not a sure thing. Did I find the leak? I was able to penetrate to where the leak is? I used some carb cleaner on cotton swabs and got it looking clean at least on one layer for about 6".

Brian: As far as internal corrosion I didn't directly address that. I only saw the rust in the trunk not at the seal. Probably like the tip of the iceberg. If I take the window out I have some kbs systems rust seal in galvanized. I can refer you to this thread. Matching silver paint..

The Three Bond I used actually started softening the rubber. I had to tape it down after a half hour.

For sure I will let you know the status of the repair, success or failure.

eatont9999 · #14 11-24-2012, 01:34 PM

My trunk seal was trashed. The trunk always had water in it after it rained hard or I went through the carwash. Yesterday, I removed the old seal, cleaned the glue out of the channel and painted the channel with Miracle Paint. I do have some rust in the lower right corner. I'm hoping the paint will help with that. I am planning on gluing in the new seal today since the paint should be dry from yesterday. I am using 3M black weatherstripping glue.

Silber Adler · #15 11-25-2012, 08:17 PM

Just a note to say that after 2 days the sealer I have used is melting the rubber seal somewhat. I may have to remove some of it and inject something else.