Hello, two years ago, the high-pressure fuel line on the flange to the injection nozzle on cylinder 4. After exactly two years and 2000-3000km, the renewed line to the flange of the injection pump ripped off again. Question: Are there special features to be considered (except screw-on and tighten)? Is there an exact tightening torque, if yes which? Thank you and greeting Information about the vehicle: MB Sprinter 312D BJ1996 700,000km