TheBishop, as far as the number of brake pad wear sensors on a given model year MB … the newer the vehicle the fewer brake pad wear sensors. Our 1995 E320 has a wear sensor on each of the 4 front brake pads, and as I recall there is one wear sensor per 2 rear brake pads. As I recall our 1998 E320 has a wear sensor on one of the inner front brake pads and a wear sensor on one of the inner rear brake pads. I chalk it up to production cost-savings.

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Fred Hoelzle