300TD found the water leak....

[fred98050]

I have been struggling for the past few days, trying to find the source of a water leak in the front passenger side panel. I read most of (if not all) the posts I could find about the subject and here is what I found....(so far)


Problem:
Water dripping along side front pax side panel (knee level)
(Here is a small video I posted earlier about the leak area:
http://web.me.com/flangenard/Site/Water_leak.html)


#1


#2


#3
Here is a shot from the inside of the dripping panel, looking straight up:



Hood hinge drain and battery area looked good. Put a water hose in there and could not duplicate the leak.
So, really looked like the windshield seal was the culprit.
I remove the windshield, found a bit of rust along side the ridge but nothing really bad or at least could not see where the water was coming from.

Then decided to take this trim out (see rubber seal):
#4



See where the trim goes inside the frame towards the hood hinge pocket for drainage:
#5



The rubber seal was broken
#6



Allowing the water to go right in there:
#7



The little white tab you see in picture #3, is the tab used to screw-in the trim piece.

#8





So needless to say, between fixing the rust on the windshield frame, replacing the windshield seal, repairing the water infiltration area and replacing (if I can find them) the rubber seals for the trim pieces.... This car is going to be inop for a while.....

What have I learned?
Next time I try the hose test, I'll put the hose right at the corner of the windshield and not directly in the hood hinge drain area.....




Cheers,
Fred

[Carpenterman]

Something new to worry about...thanks.

Seriously, though, excellent detective work.

[biopete]

Yeah thanks for this. Great write up. I think one of the improvements on the W123 to W124 model is water leakage. Can anyone concur?

[fred98050]

Just in case you have to replace them....


Part number for the trim seals:

Left: 1236980198
Right: 1236980298







Part number for screw plastic tab (one was broken): 1236900018

[Carpenterman]

I went and looked at the strip on my wagon and it almost looks like the end is a separate piece. There is a little flap connected to the end that runs a few mm up the main trim strip. The rubber end is even a different color.

At any rate, it's a wonder that MB didn't seal that body joint, rubber trim or not.

[JB3]

can you accomplish the same repair by filling that with some sealant? Would it be worthwhile to do so even if you replaced the piece of rubber? It seems like an easy leak location to happen again.

[fred98050]

Originally Posted by dropnosky

can you accomplish the same repair by filling that with some sealant? Would it be worthwhile to do so even if you replaced the piece of rubber? It seems like an easy leak location to happen again.

I agree, it looks like an easy enough spot to seal it once and for all. I ordered the parts today (from Phil) and I, then, have a few days to seal the area. What would you use?

[JB3]

Id probably use black or grey RTV silicone. Thats what I would have on my shelf, but I can't think of anything that would work any better off hand.

It seems so weird that such a place could exist. I wonder what other little leak areas there are like this. Could it be that originally that was just two solid panels butting up against eachother, and over time, the inner panel has developed some rust holes from the pooling water?

How hard was it to remove the windshield?

[fred98050]

Thanks.

It's hard to tell, but I think you are right. The sim at the 2 panels probably got weak over the past 30 years. From the inside, I can't see any major rust. I am going to put some poor15 in there and cover up with RTV.
The really weird thing is that it all pointed out to a faulty windshield seal at first.
Ran the hose in the hood hinge pocket for over an hour without any leakage... However after a good storm, my rear floor mat was soaked...


My first time removing a windshield... So, it took me about 45 min. I cut the seal in order not to damage the metal trim (read this here in the forum). I am sure that some guys probably do it in 15 minutes. Glad I did anyway, found 2 small rust areas, one on top the other at the bottom. I am using poor15 to treat the rust. I am a bit more concerned about the re-install. Don't want to mess something up. and Don't want to remove the windshield ever again....