The vacuum brake booster has become redundant, while the brake pedal and master brake cylinder become a single operating mechanism that is hydraulically uncoupled from the rest of the system by valves, and serves only to record the brake request.
Castings shown and discussed were an automotive wheel and brake caliper in 356 T6, a shift fork in A390 (high silicon), a master brake cylinder in 2014 (very low silicon), and a manifold in ADC-12, a conventional diecasting alloy.
This problem can lead to erosion of the brake lining's connection point with the brake cylinder because of trapped water with impure chemical materials in the rubber part of the brake lining.