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Master cylinder question

Posted: Sat Jul 02, 2005 8:59 am
by acadia81
I just rebuilt the front brakes on my 81 CBX, including new braided lines and I rebuilt the master cylinder. I can't get the m/c to pump fluid. I've cleaned the m/c thoroughly and blew it out. If I put my finger over the port and work the lever I can feel pressure and vacuum, and just a dribble of fluid.

Does the m/c need to be primed or bled, like an automotive m/c? There are two ports in the m/c under the resevoir, one large and one very small.

What does the small one do? Thanks for the help.

Master cylinder

Posted: Sat Jul 02, 2005 10:56 pm
by Gtrpicker
I had the same problem with my 81.

Use a fine needle to clean out the small hole in the M/C it gets block with old fluid and the cylinder will not pump up pressure. Don't put too much pressure on the needle, you don't want the point to break of, the hole is very small. ( and how do I know that the point might break off, hmmmmm)



Your M/C will work fine once the holes are clear



Michael

Re: Master cylinder question

Posted: Tue Jun 09, 2009 9:28 pm
by Mike Cecchini
acadia81 wrote:I just rebuilt the front brakes on my 81 CBX, including new braided lines and I rebuilt the master cylinder.
<snip>
Thanks for the help.
How did you get past the rubber boot and get the m/c piston out ?

Thanks..... Mike

Posted: Mon Jun 15, 2009 3:34 pm
by Mike Cecchini
I managed to use a very fine jewlers screwdriver and very carefully pry on an exposed edge of the rubber boot......and it came right out.