I plan to keep this E400 RWD beyond 10 years.
2023 will be the final decision if I want to proceed beyond 10 years.
All this time I learn a bit here and there from this forum and my own findings.

The need to maintained ones most of you probably know already :
01. The 2 sunroof water drains.
02. Keep clean the water discharge pipes from windshield wiper area all the way down to near fire wall.
If you park all the time under a tree, do watch out.

Now for what we can't maintain but will eventually leak in heavy rain.

When I first got this car in 2018, something I noticed.
The front SAM ( I am on a right hand drive car ) box has sign of rust. Dumb of me back then, I should have used Ebay UK ( right hand drive ) to see a 360 degrees view of how the
splash proof box containing the front SAM N10/1 is designed. Only recently I realized eBay used products can be a powerful visualizer tool, as the case with wiper system assy whend doing wiper adjustment.

IMAGE 1

Forward few weeks ago, I started to catalog all possible water sealing surface/media which will dry or rot overtime with age.

This is how the front SAM box looks like in complete detail.

IMAGE 2 - thank you to the photo owner at Ebay, whoever you are.
Look at the grey seal, that is kinda foam type material and not something as good as silicone. If you want to feel it you can, try it at the air conditioner blower intake side at firewall.



IMAGE 3


It has a water drain hole on its bottom

IMAGE 4

Regardless that this box for front SAM has a water drain, the circuit board on a N10/1 front SAM will corrode simply from condensation.
I seen on youtube how that circuit board looks like and it has no water vapor protection coating like some good marine electronics have for the circuit board, it is just like any PCB board home use.

What I feel upset about is, whoever design this splash proof box for N10/1 is an idiot. He created a mini water pool, that is how the anchor point of the bolt can rust, see IMAGE 1.
If only a 2mm x 2 drain holes are made at that mini water pool bottom, it will drain water fast. The problem is and I do not know if this applies for Left Hand Drive car, the wiper rotating shaft ( driver side for my case )
will leak water to firewall no matter what, when wiper in use. The seal at the wiper shaft can't handle the shaky-shaky motion of this wiper driver side. I have mentioned this on the wiper adjustment thread that such crude design will never produce a proper true smooth spinning shaft.

The water leak is not much, few drops here and there but enough to produce water level high enough to corrode my bolt anchor point as per IMAGE 1.

The other sad part is, if we have a leak and that mini pool has water, and then the black cover of this box, its seal is somehow aged and no more submersible grade,
water can enter from the black cover of this box. Splash proof is one thing, water submersion is another level. I am diver and when it comes to seals or o-rings for my
torch, video lights and underwater cameras housings, I do pay attention to them these super important make-or-break small engineering items, religiously.


Look at the potential water level build up at that mini pool. If Uncle Murphy doesn't like you............. hhhmm = expensive IMAGE 5

So, since I can't in anyway "maintain" the box grey seal to firewall.
At the least I can do is, try to deflect as much water as possible so that that mini pool can't hold water.


I will get a black one in lieu of blue. But blue becomes a good reminder ... LOL. IMAGE 6


DIY simple fix until I have a more elegant idea.

IMAGE 7
See the cable grommet on the right where I wrote slope up, MB engineers did another dumb-azz design here. Close up look of the cable grommet is at IMAGE 3.
Unless a cable grommet is a cable gland of IP67 rating, don't ever point it up like that to challenge water intrusion. Above this location is the wiper arms, water can drip down from the wiper assy.

=========================================


NEXT area to watch for water leak. Same grey seal used by MB. HVAC Blower, firewall, passenger side for my right hand drive car.

IMAGE 8A This side mate to firewall



Thanks to photo owner at Ebay, whoever you are. IMAGE 8B - This side face engine bay P/N HOUSING : A 212 830 02 44 if right hand drive
The two rectangular openings are where the funny shape water & noise diverter/baffle box above battery will mate.

This so called HOUSING if the seal has a minor failure/leak, I doubt we can tell.
The blower will splash/push the water to the cabin filter and that filter may harvest mold and host a party for all its "friends" and we get the "welcoming" smell.

This HOUSING leak already occurred to a C-class W204 of 2012, at least that is what I found in utube.



Okey dokey.... have a leak free Sunday guys

 

There are numerous W212s on this board that are beyond 10 years old now and I don't recall seeing any front SAM issues due to water... so maybe there actually is nothing wrong with this?

 

Well this is just something to think about, when it comes to a seal, leak it will overtime.
So if say u want to keep the car for 20 years, seek potential seals which may leak and sort it out.

With the drip hole inside the SAM box, it is difficult to flood the SAM, but when condensation cause erratic behavior of the SAM, that is a big headache.
I come from a yacht maintenance background among others, so water leak and condensation damage is a real pain and expensive. So I tend to be extra cautious.

 

Oh I agree with you. My car is under warranty until 10/2023 and that's my decision point as well. So far I am really enjoying it, but by that time I will probably be ready to move on. I only have 45,000 miles as of today.

 

I am having this issue. I will have to try your hack as water is now to the driver footwell. My w212 E550 won’t start. It’s in pre safe mode. Dashboard comes but no crank…it has rained heavy the past couple of days, and I have noticed the leak through the wiper seal as you stated. I could drill bigger drain holes as a possible fix, or what are my options, is my Sam unit done?!?

 

Try reading this too :
https://mbworld.org/forums/e-class-w...oof-drain.html

 

people have also reported defective windshield mastic coming up loose anywhere around (sides, bottom or top).

So start soaking from the bottom cawl moving upward over windshield, pillar and roof.

Whatever comes up keep the inside as dry as possible to save multiple poor connections from acting up later.