I have replaced the needle assembly on a G4226A Autosampler. There is now a leak from the fitting of the loop capillary. I have tightened the fitting of the loop capillary as tight as I can, without risking damage. After 6-7 attempts, with the same new needle assembly, it is still leaking. It is a small leak that isn't affecting the system pressure. Over time, the liquid will reach the leak detector.