Hydraulic system (120) for a vehicle comprising a vehicle hydraulic circuit (122) among others for the hydraulic supply of connecting means of an automatic coupling means, wherein the connecting means is designed to connect a coupling means (31) of the vehicle with a correspondingly designed coupling means (32) of an add-on unit and an operating hydraulic circuit (121) for supplying at least one Power-Beyond coupling, wherein the vehicle hydraulic circuit and the operating hydraulic circuit are designed independent of one another and each having a hydraulic pump.