A local mechanic quoted me $300 to replace the leaking mono valve in my 87' 420SEL. Not wanting to put up the cash I pulled apart the valve with some help from you guys (thanks). Inside I found some calcium deposits. I scraped it clean with the tip of the the same flathead screwdriver I used to pull out the valve. Now the monovalve doesn't leak anymore and I can justify spending $300 on somthing a bit more fun!
I hope sombody gets some use out of this post