I started out using the breather bolts but ended up removing them. The effectiveness of them seems to vary depending on the bike, oil level and riding conditions. I was ok unless I did any long distance rides in the 75 to 80 mph range. On road trips I would experience misting which I didn't like. I finally just installed a brass T fitting and ran a single line to the ground, problem solved. I have been very happy with my 587 high flow AC and DK Custom's has excellent customer service.