The hydro swing arm system prevents chafed or ruptured hydraulic hoses caused by increased stress in the swing area to the trailer. This eliminates the need for abrasion and kink protection measures, as well as the additional installation of strain reliefs and mounting clips. Easy mounting in front of the fifth wheel, also as a double or triple version, is guaranteed. The hydro swing arm is characterized in particular by the fact that it takes over the swing movement and the oil flow to the trailer.