What is the usual finish for hydraulic master cylinders internal bores. Say a brake master cylinder. Would reaming be good enough? Material is 303
cheers T.Alan
master cylinder finish
Mar 06, 2008
5 Replies
Considering a brake hone uses stones of about 320 grit, I expect reaming would be OK
Usually they are honed with a Sunnen hone. Usually the point is to remove any striations or rings (lines going either along the length of the cylinder or around the bore).
Well, yes, but a certain fine finish is desirable, and a mirror finish is not.
Yes I researched that and found out that there are two issues at play. One is the obvious piston seal deterioration by friction with a rough bore surface, the other is an increased stiction for the o ring seal when the bore surface is too smooth. These two issues work against each other and there is a happy medium. Somewhere I saw the figure of 20 micro inches or an Ra of 5. Can anyone confirm or shoot this down?
cheers T.Alan
I wrote Raybestos tech dept, awaiting answer
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required