[Got the Bug]

I had the same problem. I called Wilwood and they recommend dipping the top and bottom portion in boiling water (including the O ring) and then assembling it and tightening the clamp.

If you tighten the clamp too much, you'll end up distorting the plastic and it will never seal and you'll have to buy a new one.

I finally got mine to stop leaking. The part is a POS and if it ever leaks again I'll swap it out for something else.