Hydraulic power wheel brake unit has by-pass connection and valve to permit application of hydraulic power from main cylinder directly to wheel brakes

摘要

A hydraulic power wheel brake unit comprises an electrically operated pump (6) with at least one control piston (7) and magnetic coil. There is a by-pass connection (3) and by-pass valve (4) between the main cylinder (1) and wheel brakes (2) that applies hydraulic pressure directly from the main cylinder to the wheel brakes in the event of a failure in the electrical operation of the pump.