Uni-washer no longer wasterproof due to ice damming. HELP!!! - PeachParts Mercedes-Benz Forum

ChrisArnt · #1 02-26-2011, 07:47 AM

Yes, I did search before posting.

My wiper motor shorts out when it rains or I run it through the car wash. I then have to dry it out with a blow dryer to keep it from blowing the fuse.

It all started when we had this ice storm a few weeks back that caused severe ice damming on my house. I can only assume the same happened with the seals on my uniwasher.

I inspected the windshield seal and it was coming up a bit. I resealed it with black silicone. Having had several older cars: W123s, w110, Type II VW, BMW 02, I am pretty handy with black silicone.

I see a seal online, but have no idea where to start or if it is even for the uni washer.
There is a rubber boot looking thing below the uni-washer housing, but it doesn't look like it is supposed to be weather proof. Here is the whole thing for reference. It is the black boot below the metal washer housing. If I were to silicone this I think I need to get the metal housing piece up.

JohnM. · #2 02-26-2011, 05:24 PM

I would grab whatever parts/seals you need from a junkyard car, and use the junkyard car as reference. You should not have any problems like this on a W124. My car sat outside through 3-4 winters and never had a problem, torrential rains, etc. Although sometimes it would work really slowly when packed with snow, but I think this was more to do with my aging alternator. I don't know exactly what seals the wiper, but your previous owner or PO's mechanic may have broken/lost these pieces.

ChrisArnt · #3 02-28-2011, 07:52 AM

I've had this car for 5 years and it has always been an outside car, so I don't think the PO has anything to do with this.
Something happened this last storm made the car's windshield wiper system somehow not waterproof.
I suspect that ice damming lifted a seal.
After the car gets wet, the windows and seats work fine, but the moment I touch the washer lever it shorts after moving 1 cm.

It seems like this is very uncommon or I would have more comments.

I guess I will break out the black silicone again.

JohnM. · #4 02-28-2011, 11:36 PM

Replace the wiper motor! It's supposed to be a sealed unit. The cold may have cracked the motor housing/casing. The front wiper area of the car is not waterproof by any means, so slathering black RTV everywhere is not going to do anything.

ChrisArnt · #5 03-01-2011, 03:14 PM

I appreciate your advice, but I don't agree.

This car has been in all kinds of weather and kinds of temperatures.
From Montreal City, Quebec to Mata Moros in Mexico.
It was not particularly cold, nor was there any huge temp fluctuations.
Therefore I don't see why the motor housing would just mysteriously crack.
I think I will examine the cabin air intake and replace the air filter while I'm there. Maybe I will see some gaps or lifted seals.

JohnM. · #6 03-01-2011, 10:34 PM

Its not a matter of "mysteriously" cracking, its a matter of a system failing due to in part, inclement weather. If you want to look at it that way, every part fails "mysteriously". I have washed my car in -20F weather and had the entire car frozen over in a layer of ice minutes after, no problems. I have driven through rain so hard multiple times, that everybody was pulling over to the side of road because visibility was no more than 1 ft in front of the car. You should never have to use black RTV. I have owned Aircooled VW's too, and when I could have used RTV I just replaced the parts/pieces that were bad and problem was fixed. Don't be lazy and think you are smarter than the millions of dollars that went into R&D on these cars! Why do you think you got no results in your search and no other responses in your posts!

ChrisArnt · #7 03-02-2011, 03:49 AM

The reason nobody is answering is that nobody knows.
I think it's irresponsible of you to just say "Replace the wiper motor!"
As if that didn't cross my mind and I didn't talk to the local Mercedes Guru Heinz about this.
He said in a very quiet German accent: "Somethings f@cking wet in there and it could take me hours to find it"
At $90 an hour I'm sure as hell gonna try to solve it myself first.

So, you stated your opinion i read it and I disagree, now please drop it and leave this open for someone who has another idea.

Don't knock the black silicone, it rejuvenates door seals, fixes cracks in the dash and spread nice on toast.

JamesDean · #8 03-02-2011, 05:56 AM

Your issue is electrical. Water gets to an electrical component of the wiper system and shorts it out or causes it to stop working. Water would not effect the gear system to a point where it would not work wet but would work dry. If anything it would imped operation when dry as the water would dislodge/remove the grease. Unless some parts of the transmission assembly are broken and somehow dry helps movement...gotta be electrical.

The only electrical component of the wiper system is the motor itself. This is from a w201. Its most likely very similar to the one thats on a w124/etc

Here you can see the wiper, wiper transmission and motor. The motor sits near the edge of the windshield, which makes it possible that water is falling on it and somehow getting to its internals.

I recommend taking the cowling off and observing the system dry, and wet.

ChrisArnt · #9 03-02-2011, 07:16 AM

Thank you. I'm pretty sure that water is pooling somewhere and shorting out an open connection. It takes several days to dry or about 25 minutes with a blow dryer.
I didn't know that the entire cowling off.

ChrisArnt · #10 03-02-2011, 01:23 PM

Check out these pics. The driver side cabin air intake shows a gap that is not there on the passenger side. on the right hand edge. Could this be the problem? It looks like it is located where the motor is on your pic above.

Drivers side intake See the gap along right edge.

YES I REMOVED THE RUBBER SEAL TO LOOK AT THIS>