Abstract: A master cylinder assembly has a low pressure, high volume displacement quick take-up chamber and a high pressure, low volume displacement pressurizing chamber formed by a stepped bore and a stepped piston. A compensation control and blow-off valve unit has a peripheral lip seal type valve providing compensation flow on brake release but preventing flow from the quick take-up chamber during brake apply. A valve body is integrally molded as a part of the reservoir. A normally closed check valve can open to provide communication between the quick take-up pressurizing chamber and the fluid reservoir. When the pressurizing cup for the high pressure chamber closes its compensation port, the check valve is subjected to the pressure in the quick take-up pressurizing chamber. Initial fluid flow is obtained from the quick take-up chamber past the pressurizing cup into the high pressure chamber.

Abstract: A brake pedal lever assembly having a cam surface engaged by a cam follower on one end of a master cylinder push rod and so arranged that as the brake pedal lever is moved in the brake actuating direction a cam also on the pedal lever moves the push rod cam follower upwardly toward the brake pedal lever pivot point, increasing the brake pedal lever ratio. A modification has a jointed pedal lever which yieldably resists bending movement. When the bending movement does occur, the cam moves the push rod cam follower at a faster rate, increasing the pedal ratio at a faster rate.