Front Brakes-1993 CBR900RR

[GregsGSXR]

My riding partner is having a problem with the front brakes on his 1993 CBR900RR. After a few pulls they lock up completely and you have to undo the bleeder valve to unlock them. Once you release the pressure at the caliper they are fine again. We were thinking the master cylinder or calipers so we took and cleaned everything very good. Same Problem. I was just seeing if anyone has any suggestions on what may be wrong or where to get an aftermarket master cylinder....already tried Steeles.

[Devaclis]

There is another member on the board here with the same exact issue but on the rear brake. Try filing doen the bottom of the bleader just a small amount. Then put it back in. Do not overtighten!

[TFOGGuys]

You have a blocked return port on the master cylinder. You may be able to clear it with compressed air, but more likely you will have to disassemble the master cylinder, including the plastic fitting where the reservoir hose attaches to the master cylinder, and clean the ports carefully with a piece of very small diameter wire.

[GregsGSXR]

Thank you very much....sounds like a job for the weekend.