Brake lubrication system

A shoe drum brake actuator comprises a camshaft mechanism (34, 35) contained within an actuator housing (54) and a tubular member (36) which journals the camshaft. A lubricant fitting (14) permits lubricant to be introduced into both the tubular member and the actuator housing. In addition, an automatic adjuster is contained within an adjuster housing forming part of the actuator housing (54) and a pressure responsive valve (144) is provided to permit lubricant introduced through the lubricant fitting to be discharged from the adjuster housing, when a predetermined system lubricant pressure is attained. A compressible device (143) is contained within the actuator housing (54) to compensate for effective volume variations and precluding the exhaust of lubricant and the introduction of air during such changes.