Topic: Cb650 brake bleeding

[club_c]

I just changed out the front brake master cylinder on my 1980 CB650. I cannot get to a solid lever, it seems there is air in the system but cannot purge it. I’ve done lots of brake bleeding in the past. This one seems to elude me. Any good techniques unique to this model?

[newday777]

First off you need to bleed the master banjo bolt of air just as if it's a bleeder. Then bleed the caliper after.

[fizzlebottom]

Do you have the original rubber hoses?

If so, those might be your problem. They shed the inner lining and end up bulging under pressure. I had this exact issue when I was doing my front brakes many years ago, even after a new mastery cylinder and like 2 hours of bleeding. I had SS brake lines fabbed up by a local dude and my front brake was 100% fixed.

[scunny]

on my 650 withe duel discs, i had to use a 50cc syringe to bleed the calipers, worked a treat.

[newday777]

I just changed out the front brake master cylinder on my 1980 CB650. I cannot get to a solid lever, it seems there is air in the system but cannot purge it. I’ve done lots of brake bleeding in the past. This one seems to elude me. Any good techniques unique to this model?

Did you get it working?