The invention relates to a motor-pump unit for a motor vehicle brake system, comprising a motor and a pump which is provided with a shaft that is driven by said motor, with the shaft end being rotatably mounted by means of at least one bearing in an accommodating member having valves and connecting channels, said shaft driving displacement means which are disposed in a chamber that can be filled with pressure fluid. In order to improve vacuum filling of the brake system with pressure fluid, the invention discloses that the shaft end terminates into a free space, and that at least one connection is provided between the free space and the chamber.