Abstract: A process for the precise adjustment of the lost travel of a piston in a master cylinder. Master cylinders typically include a number of components in spatial series arrangement, with all components having individual tolerances. The individual tolerances regarding the lost travel of the piston or pistons, can combine additively in the master cylinder. The resulting lost travel, hence, is relatively large and varies with individual master cylinders. The process provides that the lost travel of the piston or pistons in the master cylinder can be precisely adjusted and, hence, can be kept very low. The position of the piston or pistons is measured in the condition in which they just seal the associated equilibrium ports. Subsequently, the position of the pistons is calculated in consideration of the desired lost travels and, by adjustment of the force planes acting on the desired point, the resting position of the piston and pistons, respectively, is fixed to the desired distance.

Abstract: A brake booster is dislosed wherein the risk of damage to the control valve housing of the booster in the area of the support of the guiding sleeve which guides the push rod is precluded. The guiding sleeve of the booster comprises an axial extension which, while accommodating the pressure plate and the reaction disc of the booster is located, in sealing manner, in the axial bore of the control valve housing of the booster.

Abstract: A power brake unit for an automotive vehicle comprising a booster utilizing the pressure difference between a vacuum and atmospheric pressure including a vacuum casing composed of a cup shell and a cover shell, and a master cylinder secured to or formed integral with the cup shell. The entire unit is fastened to the splash wall of a vehicle by a fastening means secured to the cup shell adjacent the master cylinder. This fastening arrangement reduces substantially lost travel of the brake pedal due to extension of the vacuum casing in prior art power brake units caused by brake actuating forces and enable employment of lighter weight materials for the power brake unit.

Abstract: To reduce the load or force exerted on the housing of a vacuum brake booster, the master cylinder housing extends axially through the booster housing thereby connecting the two end walls of the booster housing together. The master cylinder housing is directly attached to the splashboard of the vehicle. The movable wall of the booster sealingly surrounds the housing of the master cylinder and acts on the housing of the booster control valve via tie rods extending axially through the end wall of the booster housing adjacent the splashboard and connected to a yoke fixed to the adjacent end surface of the housing of the booster control valve.