Hello, problem: In my 350er, the holes of the brake disc appeared to be fitted with brake dust. I determined it yesterday when I was driving backwards from a parking gap and had no braking effect. In further driving during braking, the pedal imme harder when I was standing on the brake longer or several times successively on the brake. As soon as the discs seemed to cool down, the pressure point was back to normal. The question now arises: Why do you sit down? The holes close themselves and how can I get them clean again without immediately unscrewing the wheels and tediously popping out the dirt with a screwdriver.