NDDan
Guest
Well. I believe problem has to be in lower side. You have eliminated the small needle and seat. Now you have the nylon check valve and second stage poppet along with its seat that can give you the problem. Replace nylon poppet first. Then you better have a good look at second stage poppet and the orings that seal it up. I believe the seat for second stage poppet on lower side is loctited in and may be extremely hard to remove. If it should be leaking around the seat it will have to be removed and loctited back in. Good luck