Cartridge of a mechanical actuator of a vehicle brake

The cartridge has a cage (40) moving in rotation around an axis of a cartridge body (24) between fixing position and release position in which the cage is released from the body. The body includes a circumferential abutment limiting rotation of the cage. An axial bracket (44) of the cage cooperates with the abutment when the cage is in its release position. The body comprises a ramp forming projection (60) adjacent to the abutment such that the axial bracket is supported radially at same time on a fixing projection (42) and the ramp forming projection in the release position of the cage. An independent claim is also included for a braking device for a motor vehicle, comprising a hydraulic actuating cylinder.