Brake wear sensor

A vehicle brake assembly comprising a rotatable braking member, a friction brake lining having an operative face adapted to be applied to said rotatable braking member and actuating means for applying said brake lining to said rotatable braking member, adjuster means adapted to be driven by said actuating means for the purpose of maintaining said brake lining in close proximity to said rotatable braking member, and wear sensing means responsive to actuation movement of said brake assembly in a brake-applying direction, said wear sensing means comprising a sensor adapted to be operated by movement of an operating member in a linear direction, a rotatable follower member responsive to movement of said adjusting means, and a transmission mechanism for translating rotary movement of said follower member into linear movement of said operating member, wherein said wear sensing means is adapted to be driven by said adjuster means, and said sensor is adapted to be driven from a gear wheel on said adjuster means with an end of said sensor remote from said gear wheel being formed with electrical connector means, whereby said wear sensing means (unit) can be removed from said brake assembly for service without dismantling said brake assembly itself, and wherein a non-rotatable lead screw is movable in a longitudinal direction, in turn to move said operating member in a corresponding direction, and said follower member comprises a rotatable pinion which is captive against movement in a longitudinal direction, whereby rotation of said pinion in response to rotation of said gear wheel causes said lead screw to move in said longitudinal direction.