Should Sun Roof Drains easily handle rain
 

I got in the 84SD and the seats were wet after a pretty hard rain storm. Sun roof seals are definitely shot but the side seals are NLA. Shouldn't the drains handle the run off and direct it to the ground and not the seats?



I pulled the panel and cleaned the drains not awfully long ago and am surprised that the issue has returned.

Yes the point of the drains is to keep the inside dry.

There are, however, limits to the system and what it can handle.

Yes, that is the point of them. The seals are mostly to block wind noise. I'd snake the drains out again, front and back and verify with a hose that water is coming out of all the drains.

-Rog

I rodded the drains with a snake bought from HF for the purpose. The unfortunate thing is that the back drivers floor is soaked and the weather is cooler.

I'm getting close to selling to get rid of some projects and because of my 16 yr old son driving insurance rates with 6 cars licensed.

The rear sunroof drains are more problematic. You must remove the sunroof panel to access them. Not too difficult but still a PIA.

Hoses deteriorate / crack especially where the hose slips onto the metal tube on many sun roofs.

My headliner is out because it formed a water balloon the 1st time I had to learn about the drains. Hoses are good and it was warm yesterday so I flushed them. I was surprised that cleaning again so soon was necessary.

Parking under a tree outdoors?

I think the W126 sunroofs might be a poor design not capable of handling hard rain. My roommate has a 1991 350SDL and he was getting water leaking in from the sunroof. I took it apart expecting to find clogged drains or rust holes, but the drain hoses were clear, there was no rust, and hardly any sediment.

I cleaned the sunroof tray and cleared out the tiny channels under the welded-on brackets upon which the plastic deflector brackets set. During the next rain, the sunroof was still leaking.
https://lh3.googleusercontent.com/8s...4=w800-h453-no

It appears the sunroof trays on the W126 are far too shallow, and the path which water has to flow is too narrow for water to drain into the hoses rapidly enough.

Water drips from the very front of the sunroof. When I pour water into the front center of the tray, it overflows over the edge before the water can drain to the area where the hoses are.

All I can suggest is maybe cutting off part of the metal sunroof deflector bracket perches and grinding away at the plastic deflector brackets so the water can drain faster, as Mercedes couldn't get it right on such an expensive car, while previous chassis were adequate. I guess it's another example of newer cars not always being better.

Re: Fitting sunroof seals


I did this on a W123 by removing (well half removing) the tray - seemed like loads of extra work but when I read how other have struggled trying to fit them it does make me wonder

As stated elsewhere in this thread, MB sunroof seals are not intended to be watertight. That is why in the W123 they have four generous drain paths. Don't know for sure about other models.

The seals are in place mainly for wind noise reduction. Anyone who has driven a W123 without those seals will understand.

While the seals aren't intended to be water tight, they do keep most of the water out I would imagine. Perhaps the issue is that the seal has deteriorated to the point of letting in more water than the drains were meant to accommodate?

Interesting! My SD also had water inside of it via the sunroof when we had massive rain dumped on us recently.

Does anyone have good shots of the rear drains?

Pierre Hedary recentle posted a video on how to clean the drains

Good front and rear seals will channel most of the water to the side trays. I don't believe the front and rear trays can be faulted if the seals are bad since they were designed to have good seals above them to greatly reduce the water flow.