Abstract: A disc brake includes a housing which straddles a braking disc and is slidably mounted in a torque taking member. The housing includes a brake actuator mechanism having at least one adjustable tappet assembly. The tappet assembly extends through a bearing aperture and a cover plate and is sealed thereto by a seal assembly. The bearing aperture is defined by the inside wall of a bearing projection formed with the cover plate. A lever and eccentric arrangement operates the tappet assembly via a force transmission member located in a groove in the eccentric. An intermediate member also located in the groove carries a gear drive which operates an adjuster mechanism for the brake.