Abstract: A brake actuator for use in railway transit and similar vehicles to adjust for wear of braking components located on such vehicles. The brake actuator includes an externally threaded or serrated rod having a longitudinal axis. Such brake actuator further includes power and slack adjusting collets disposed on the rod and located in respective housings disposed about the collets and rod. A yoke member is disposed about and in engagement with the power collet housing and a first axially translatable bearing is disposed on the yoke member. A second fixed bearing is spaced from the axially translatable bearing and a piston is disposed for movement in a direction generally perpendicular to the longitudinal axis of the rod. The piston has an integral fork-shaped wedge disposed astraddle the threaded or serrated rod for movement to a location between the bearings.