Motorcycle Repair: break fluid leaking, honda cb400t, cylinder body

Question
Hi Bill,

    I recently bought a 1981 Honda cb400t Hawk as my first bike. When I got it the front break system was shot so I rebuilt the caliper and the master cylinder and put a new brake hose on it. Now the brakes are working fine but fluid is slowly leaking out where the brake hose meets the master cylinder.

    There is a 1 washer between the brake hose and the master cylinder and a 2nd washer between the brake hose and the screw. The fluid looks like it is coming out of the washer between the master cylinder and the hose, but when I had the system apart it didn't look like there was anything wrong with the washers.

    So my question is could the washer be causing this problem or does it sound like I need a new cylinder body(hopefully not!)? Anyway I would just like to get your opinion before I do anymore guess work and waste money. Thank you so much in advance!...Jim

Answer
Jim, Honda usually recommends replacing the copper sealing washers on the brake lines, even when they look good. They may be available at an auto parts store. You might try to crank down on the bolt a little more, but I would double check for debris or damaged sealing surfaces, first.

Otherwise, take the washers off, see if you can file them flat and try it again, with a little more muscle. I have often reused them in the past, but sometimes they do need replacing.

Otherwise, you could have cracked the m/c housing (ouch) or perhaps the line end is damaged in some way.
Clean everything carefully, inspect for damage, replace the washers and it should be fine.

Bill Silver