Brake Master Cylinder for a Motor Vehicle Brake System with Profiled Pressure Piston

A main brake cylinder arrangement for a vehicle brake system, comprising:

• a main brake cylinder housing having a cylindrical recess,
• at least one pressure piston which is movably and sealingly guided in the cylindrical recess of the main brake cylinder housing along a longitudinal axis, and
• a fluid reservoir for storing a brake fluid, the fluid reservoir being fluidically coupled to the main brake cylinder housing via a fluid channel, wherein
• the at least one pressure piston, together with the main brake cylinder housing, encloses a pressure chamber in a sealing manner, which pressure chamber is or can be fluidically coupled to a fluid circuit of the motor vehicle brake system, and, depending on the position of the associated pressure piston, is fluidically coupled to the fluid reservoir or disconnected therefrom,
• a sealing arrangement enclosing the pressure piston is provided between the outer circumferential surface of the pressure piston and the cylindrical recess in the main brake cylinder housing,
• in an axial region that spans the sealing arrangement in the axial direction in a starting position of the pressure piston, the outer circumferential surface of the pressure piston is furnished with profiling that provides a fluidic connection between the fluid reservoir and the pressure chamber,
• the profiling is furnished with surface area sections which are situated at different radial levels with respect to the longitudinal axis, and
• at least one axial indentation is provided in the sealing arrangement and/or in the area of the profiling of the pressure piston.