In order to provide a starting system for starting a parking brake of a motor vehicle, the starting system requires as few as possible simple, reliable and economical components that are less susceptible to failure and require less installation space and the system The build complexity is as low as possible, and enables the parking brake to be easily actuated and integrated into the main assembly of a motor vehicle drivetrain, as well as a simple method for locking or unlocking a parking brake that allows the actuator. The element has a mechanically acting actuating mechanism and can be coupled to the pump drive of the hydraulic system of the main assembly via adjustable clutch means by means of an adjustable clutch arrangement in order to actuate the parking brake.