Hydraulic brake system

A hydraulic brake system, comprising a master cylinder actuatable by muscle power, as a brake force set-point value transducer for external force braking events, a disconnection valve, downstream of the master cylinder, said disconnection valve disconnects the master cylinder from wheel brake cylinders during an external force braking event, an external energy source, intended for external force braking events, to which the wheel brake cylinders comprising the wheel brake pressure control valve assemblies are connected, wherein the wheel brake cylinders in the event of a failure of the external energy source can be acted upon with braking pressure by means of the master cylinder, a simulator spring element, said simulator spring element forces a piston of the master cylinder into its basic position and brings about a travel/force dependency at the piston that is similar to that of muscle-powered or power-assisted brake systems, the piston (34, 36) of the master cylinder (26) has a lengthened idle travel, and the piston (34, 36) builds up no pressure in the master cylinder while the piston is traversing the idle travel, and an external force braking event takes place while the piston (34, 36) executes the idle travel.