2001 S430. I was getting water on the front passenger mats and was curious as was not running the AC(as if the AC drain hose fell off.) I opened hood and noted the air baffle was full of water(from recent rains.) I cleaned out the gunk and found a large plugged drain. I opened it and the water drained under the car. My question is that did the water that overflowed go through the cabin air filters behind the glove box(do I need to pull the box) or am I ok and the water took a different route to the floor?
Also do I get at the charcoal filters from below?
Thanks

Sounds like a good reason for water to get in. Those drains can clog real easy if you park under trees at all.

Check out this training document for more than you probably want to know:
http://www.mercedestechstore.com/pdfs/507%20Systems%20I/507%20HO%20HVAC%20220%20(ACB,%20IC)%2010-30-02.pdf

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

MB issued a Service Campaign in March 2001 instructing dealers to check and clean the reed valve at the bottom of the air duct/water collector. I don't know why, but this procedure was never added to the list of items to be inspected during regular maintenance.

Nearly every time we get heavy rain, I get a 220 S-Class or two towed in. The reed valve at the bottom of the water collector gets clogged and the level eventually rises until it reaches the fresh air intake. It then rains down past the cabin filters and blower motor, onto the passenger front floor. If enough water gets in, it soaks through the floor carpet and works it's way toward the rear SAM/fuse box. This can cause a wide variety of problems from the engine not starting, to various rear lights staying on. I had one a few years ago that actually melted the wiring and fuse box due to a shorted rear defroster relay.

lizem100, I'd strongly recommend removing the rear seat bench, and checking for water in this area. It only takes a few minutes to check, and you could wind up saving yourself a major headache. In a worst-case scenario, the typical parts needed are the cabin filters, blower motor, rear SAM, and rear fuse box. The tow-away sensor might also get wet, but that takes lots of water. The carpets will also have to be removed to dry them out. Cosidering that it's an S-Class, the $$$ damage isn't as bad as you'd think. Hopefully, you won't find any water, but if you do let me know.

There are two simple ways for S-Class owners to avoid this potential disaster. First, check the reed valve regularly. If you live in an area where the seasons change, check at least once a week once the leaves start falling. All it takes is a flashlight and some stiff mechanics wire. It takes all of three minutes.

An even better safeguard is to drill a few small holes in the side of the duct, below the level of the air intake. By doing this, even if the reed valve does become clogged the water will leak out of the duct before it reaches the fresh-air intake. There are work for instructions detailing the MB approved procedure in WIS.

Gentlemen- thank you very much.
Stevebfl-excellent link.
ILUVMILS thanks for the advice
Questions- should I pull the rear bench if just the front part of the passenger front mat became wet?
Also does it follow automatically that the cabin dust filters got water on them and they need to be changed?

Yes, you should take a look under the rear seat. It only takes a few minutes to check, no tools needed. And yes, the cabin filters should be checked as well. Any water that made it to the floor most certainly passed through the filters. After all, who wants a smelly, musty, moldy smelling 220?

I pulled the rear bench. It was easy to push up on a tab on each side. I found a bunch of coins, old food bits, and 2 business cards. Under the bench was a 1/4" thick of saran like plastic. Under that was a 1/4" sheet of rubber which covered several sheet metal boxes of electronics. I did not want to pull the rubber off all the way as I did not have a supply of the plastic fasteners which looked fragile. I put my hand down between the boxes and in holes to feel for moisture. I did not feel any but I did not pull the boxes.

I pulled the carpet in front. I lifted it just in front of the seat but did not pull the carpet up at the sides. Underneath the carpet is several inches of foam which I take to be sound deadening. The carpet was dry but the bottom part of the foam was wet still after about a week. I put a towel in there to get air circulation. The metal flooring was dry. I seem to remember their was a drain on the floor to the outside.

On startup occ the A/C blower squeaks. Is it history or can I oil it by pulling the glove box? Do I need to pull the blower(if so how) to oil it or is oiling easy?

I will pull the glove box as apparently the filters must have gotten wet.

Any other things I need to do?