[Hectic]

Also how is the seal around the hop rubber, barrel, hop unit?
Put the rubber on the barrel put your finger over the end of barrel and blow through the hop end. See if air is escaping between rubber and barrel.
Dont worry if a lil is escaping. Put the hop up on and do the same. Plug barrel and blow through hop assembly with the barrel plugged. If there is still leaking put a wrap of teflon on the barrel install the rubber and put another wrap over the rubber where it ends on the barrel side not the feed side and reassemble. Should be air tight.
Im sure you likely know that but its something thats overlooked at times