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Motorcycle Repair/CBX brakes stick


My 80 cbX front brakes are sticking and I believe the master cylinder (mc)is plugged. Ive taken the cap off and it looks a lot different than other Honda mc Ive seen. What is the correct way to unplug a cbX mc or rebuild it?
Thanks so much, Terry

The master cylinder rebuild was covered in a CBXpress a few years ago.  You can also go to the website to see some pictures and get help.  rebuild kits are around $50 on ebay.  There is a very small orifice that allows the fluid to move from the lines into the reservoir, if that is plugged, then the brakes will apply harder and harder as the temperature goes up.  The brake fluid should be changed annually.  The white (yellow) plastic part can be lifted off the aluminum container but have a replacement ready in case it is damaged or cracked. If you just want to unblock the small orifice, rotate the white plastic 90 degrees and you should be able to see the hole through the holes in the plastic in the bottom. Replace the 'O' ring since it will have dents in it from corrosion product and will likely not seal properly again.  Brake fluid does a nasty number on paint, ensure the parts are sealed and tight before going for a ride.

Good luck,  Jan

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Jan Ringnalda


PLEASE NOTE: PLEASE READ THIS!!! I can help with questions ONLY on any Honda CBX-1000 motorcycle, only 1978 to 1982. OR 1981 to 1983 Honda CB1100R models ONLY Honda CBX/CB1100R motorcycles, Please NO other makes, no other models. IF YOUR QUESTION IS FOR ANY OTHER BIKE Your question MAY BE FORWARDED TO THE QUESTION POOL WHERE IT MAY NEVER BE ANSWERED. IF I ANSWERED YOUR QUESTION, and you feel the need to give me marks lower than 10, first post a follow up question. If you mark me lower, I will respond and you run the risk I will never, ever, answer one of your questions again. I'm doing this free of charge, as a service to fellow motorcyclists. If you do not value my time, I do...


Have owned over 50 of these fine classic Honda motorcycles

International CBX Owners Association, SAE, Materials Research Society

CBXPress, VLMC magazine, Used Bike Guide

PhD in Materials Science, Post-Doc in prototyping automotive components

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