If you continue to have problems e-mail me and I will send you a new valve and cupseal. But putting oil in the asa should fix it. How this problem arises is that if the cupseal and valve are dry and you fire the marker it will scrap the side and scratch the cupseal. Also Co2 will sometimes have some trash in it like dirt or something. All so if play with it and get dirt on it or paint and you change 12 grams you could get dirt and stuff in the asa that way too.