Hi, I am working with a 1290 sampler G4226A. When the needle in at the maintenance position, the pressure of the system is fine. However, when the needle goes on the needle seat the pressure drops and I can some leak from the needle seat
I placed a new needle Seat Assembly and a Needle assembly but the issue persists. I followed the advice given by the community for a 1260 ALS but it didn't work either ( Leaking from needle seat )
Any suggestion/advice is much appreciated!