Quote Originally Posted by OPBN View Post
Which part is leaking? Is it leaking from the area that screws in? If so, this is a bad o-ring.
If it is leaking from the reg, empty it out, disassemble the bonnet like you are changing the shims, and inspect the piston. If the o-ring and seal look ok, re-lube and try it again. I had a used one do that to me, but ever since I cleaned and re-lubed the piston, it has been fine. Or send it Ninja, they will probably take care of it. It's kind of fun to tinker with the shims anyway, and see what it does to the RT.