77 RD400 Rear master cylinder

[cwnist]

Has any one replaced the rear master cylinder? Is there another Yamaha master cyl that can be easily adapted?

[premiumjo]

I am not aware of any yamaha brake cylinders that are the same as the RD400 rear. You can go to http://www.yamaha-motor.com/sport/parts/home.aspx and browse through their microfiche and look for a cylinder that has a similar pedal/push rod set up that could maybe be adapted to fit. Or try http://www.hvccycle.com/hvcpartscatalog_files/yamahabrakes.htm they have master cylinder rebuild kits for $75 (scroll to the bottom of the page) They also sell a sweet little Magura unit that will fit the RD if you dont mind parting with $220.
RjD