I have a very slight leak at the banjo bolt at the top of the cylinder head. I bought new copper washers ,a bolt and the line. Still leaks. Tightened to 30 ft lb ....anyone run into this? Seems to me leaking at the interface between the head and the copper washer. I did not see any Nick's in the head. I am thinking RTV silicone on the washer unless someone has a better.idea.