NON-RETURN VALVE FOR A HYDRAULIC VEHICLE POWER BRAKE SYSTEM, AND HYDRAULIC VEHICLE POWER BRAKE SYSTEM

A non-return valve having a valve opening spring is positioned between an unpressurized brake fluid reservoir and a brake master cylinder of a hydraulic vehicle power brake system having an externally-powered brake pressure generator. The non-return valve allows for a flow-through in the direction of the brake master cylinder and blocking against a return flow from the brake master cylinder into the brake fluid reservoir starting at a counterpressure in the brake master cylinder specified by the valve opening spring.