Topic: 1980 Cb650 Front Brake issues

[southernyank617]

I just recently picked this bike up. The front brake had no pressure to it and I could hear air being sucked or blown. Looking into it further I found that when pulling the lever, air and fluid is coming out from under the master cylinder cap. I found that there are two small square notches right next to the hold down screws, one on each side. This is where the air and fluid is coming out from. I've tried cleaning the surfaces but I can't get it to stop. I'm wondering if a new cap, plate, and diaphragm  are what I need or do I need to look else where? 

[The_Crippler]

Welcome to the forums.

I'm working on the same bike, and I'd probably just bite the bullet and rebuild the reservoir part.  You could try each piece individually and hope you hit the right one, or you could just get it all as a package deal and be sure.  (Plus, you won't have to worry about another part failing right after it.)

https://www.partsnmore.com/cat_index.php?model=cb650_sohc&category=chassis

[southernyank617]

Thanks. That will probably be the best way to go.

[The_Crippler]

Glad I could help...now tell us a bit about yourself.