A great all-around rubber treatment is something called Gummi- phledge - a German product available at your local BMW dealer. Good for door seals too. Dave Swingle --- In dmcnews@xxxx, "Paul Salsbury" <paul.salsbury@xxxx> wrote: > I used a rubber/silicone lubricant, which comes in a spray can. I Cleaned > the whole diaphragm sprayed both sides and dabbed off the excess. works fine > now.