My personal experience with leakage from the washer reservoir may save you some time. The source of leakage was the brittle grommets that seal the two pumps, referred to in 'Tangas reply. However, I experienced great grief in trying to purchase the correct grommets from the dealer. They fit the preexsiting washer pumps but did not make a tight seal. I went through six sets of grommets, all slightly different in appearance. There was still some weeping. Finally, I had to change the perfectly good pumps for new pumps to stop the weeping. It was a case of MB producing "new" grommets to fit "new" pumps. Either that, or the Nylon pump housing shrank at the point it passes through the grommet into the reservoir. At first, I tried all sorts of gasketings to stop the weeping, but they did not work.