RE: Washer fluid leaks when filled
 

My '99 SLK has been a brat from the day I bought it ( April, '05). When it is running as it should, it is a nice ride, but it has proved to be very temperamental. I bought it out of ignorance...thinking that the MB name meant quality....NO, it only means COSTLY because ofits reputation for being a wealthy person's car. If I had done my homework I would have bought something else. Just look at all the postings on this forum alone! And speaking of the forum, Thank God that I did discover it. I have found lots of valuable help from knowledgable people who aren't out to bleed you dryjust want to help. I have had a Ford convertible, a Chevrolet convertible, and a Triumph Spitfire convertible and they have all been virtually trouble free!!!. ( I never spent a dime on repairs for the Triumph!!!). I could go on and on but suffice it to say that my washer reservoir leaks too. I am sure I could fix it with a bit of duct tape, super glue or perhaps an empty milk jug but I just haven't got around to it. ( My brother had a Porsche with a similar problem and the dealer wanted $140.00 to replace it. He did the empty milk jug thing for $0.00). Good luck.

Washer bottle repair
 

I've just fixed mine at the 3rd attempt. 1st attempt was to silicone the rubber grommet. That didn't work. 2nd attempt was to buy a new rubber grommet. That didn't work either because after closer inspection I found that the actual washer pump had developed a leak. I replaced this and that was the job sorted. Cost of grommet, £1.45. Cost of pump, £23. Simple repair. I also had to slightly lift the other redundant grommet situated at the front of the bottle so that it would form a seal.

Leaking
 

Firstly, I'd like to welcome you to Mercedes Benz ownership. Nothing on a Benz is cheap and I accepted that when I bought the car (by the way a new resevoir for a FORD F150 is $300.00). As for your leaking...check the grommet that the washer pump goes into...fill the resevoir as you are looking at the grommet it may be leaking because of age or heat exposure. If it is, then go to you hardware store and get some non-adhesive silicone lube and remove the grommet, clean it with warm soapy water and grease liberally with the silicone....leave a little bit on it, replace the grommet into the resevoir and replace pump motor. If that doesn't work then you have a resevoir crack. In this case, if you don't want to spend the $250 then get some JB weld and repair the crack yourself. Good luck.