Topic: CB550 Master cylinder internal ports

[Swazi]

Greetings ya'all, got a 76 CB550 with a corroded brake reservoir. I can see one internal port is obviously open, going into the piston chamber, but the other port appears not to be going anywhere. From my research of drawings, I can not tell if this other port goes anywhere. Any thoughts?
Thanks in advance
Don

[BobbyR]

There are two holes inside the resivior. you need to rod them out with a thin strand of copper wire. The piston bore can be cleaned with a gun bore cleaning brush or something the same size. Denatured alcohol is very good solvent for the dried fluid and crap. 

[calj737]

The two holes in the bottom: supply of fluid to caliper and return from caliper. The both must be completely clear for the caliper to work.