...that can help me out. I've only used mine once and it was a while ago. Today I went to use it again, and I 'think' I'm missing a piece. The plastic tubing goes through a hole in the pump and there's a knurled knob that tightens down. Is there supposed to be a gasket or o-ring in the hole the tube goes through, 'cause my tubing is loose in the hole. Thanks. If this doesn't make sense, let me know and I'll post a pic.