Jens, No I havent replaced the switch I believe is fastened to the master cylinder or some part there of. I did notice it seeming to leak a little fluid of some sort at the top of it, where the electrical contacts are. I was told to check the B Bomb by depresing the brake pedal with engine off. A certain number of pedal pumps and it gets hard denotes the Brake bomb is bad. I was wondering what goes bad in them. It sounds to me that they have pressure in them when hooked up and over years leak out?