After the repair with a new sealing ring, I had the impression that the entire hydraulic system is somehow sluggish. Overroll bar only runs up to approx. 70 degrees high instead of 90 degrees. When closing the rear cover, it needs some manual tutoring on the first 30 cm. The cylinder of the roof lock needs some support on the last 2 cm with the help of the bus key to get into final position. In the meantime, I acquired measurement technology and was able to display the pressure. When the control for the rollbar was activated, 170 bar was reached. When the roof was activated, similar values were displayed. Despite all efforts, no satisfactory result. Now the question: 1. Are the 170 bar the setpoint value, or the pressure slips past the seals in the cylinder. How can a sealing pack be repaired on the hydraulic piston? The other cylinders have no noticeable oil losses. Theoretically, there are only two possibilities: firstly, the pump agregate does not bring enough pressure or the built-up pressure loses itself by the piston seal into the chamber of the back / back stage (two ways cylinder back) Is there anything else I have not considered????