Brake system for a motor vehicle

A brake system for a motor vehicle with a plurality of wheels, a brake pedal, and a brake caliper mounted at each wheel, which comprises:

• an actuating device controlled by a brake pedal through electric lines, said actuating device being an electromechanical wheel brake actuator mounted on each brake caliper of each wheel of the motor vehicle;
• a brake piston disposed in a cylindrical bore formed in said brake actuator, a spindle drive axially moving said brake piston in said cylindrical bore between a position of repose and a position in which said brake piston is pressed against a brake lining, and a piston sealing ring limiting an axial movement of said brake piston within said cylindrical bore;
• a transformer part connected to said brake piston via a non-self-locking pair of threads;
• and
• a main spring compensating for brake lining wear disposed in said actuating device, said main spring, upon a return stroke of said spindle drive into the position of repose, moving said transformer part axially out of said brake piston while said brake piston is firmly held by said piston sealing ring.