A mechanical motor vehicle vacuum pump comprising: a pump rotor; a coupling element configured to be mechanically driven by an internal combustion engine; and a clutch arrangement which is switchable and positively locking, the clutch arrangement being configured to lock the coupling element to the pump rotor in a locked position so that the coupling element rotates together with the pump rotor, and to release the coupling element from the pump rotor in a released position, the clutch arrangement comprising: a bolt holder connected to the pump rotor or to the coupling element so as to rotate therewith, the bolt holder comprising at least one radial bolt guide and a bolt body which is configured to be displaceable in the radial bolt guide, a guide body configured to be axially displaceable, the guide body comprising a guiding surface which is inclined with respect to an axial plane, the guide body being assigned to the bolt holder, the bolt body being forced radially into a locking position via the guiding surface, and a catch body connected to the coupling element or to the pump rotor so as to rotate therewith, the catch body having at least one rotational catch depression which is configured to have the bolt body engage therewith in its locking position. a pump rotor; a coupling element configured to be mechanically driven by an internal combustion engine; and a clutch arrangement which is switchable and positively locking, the clutch arrangement being configured to lock the coupling element to the pump rotor in a locked position so that the coupling element rotates together with the pump rotor, and to release the coupling element from the pump rotor in a released position, the clutch arrangement comprising: a bolt holder connected to the pump rotor or to the coupling element so as to rotate therewith, the bolt holder comprising at least one radial bolt guide and a bolt body which is configured to be displaceable in the radial bolt guide, a guide body configured to be axially displaceable, the guide body comprising a guiding surface which is inclined with respect to an axial plane, the guide body being assigned to the bolt holder, the bolt body being forced radially into a locking position via the guiding surface, and a catch body connected to the coupling element or to the pump rotor so as to rotate therewith, the catch body having at least one rotational catch depression which is configured to have the bolt body engage therewith in its locking position. a bolt holder connected to the pump rotor or to the coupling element so as to rotate therewith, the bolt holder comprising at least one radial bolt guide and a bolt body which is configured to be displaceable in the radial bolt guide, a guide body configured to be axially displaceable, the guide body comprising a guiding surface which is inclined with respect to an axial plane, the guide body being assigned to the bolt holder, the bolt body being forced radially into a locking position via the guiding surface, and a catch body connected to the coupling element or to the pump rotor so as to rotate therewith, the catch body having at least one rotational catch depression which is configured to have the bolt body engage therewith in its locking position.