My master cylinder is having issues. It is after market, and I've had it for about 3 years. Not to many miles on the bike since installing (maybe 5000). The brake lever started rattling really bad and the brake lights stay on unless I hold the lever out all the way. I checked the switch and it's not broken. The little plastic piece is there on the end. I switched brake levers and it doesn't rattle any more, but it still won't release all the way to turn the lights off. I've heard that you can get a build up on the spring that pushes the piston back out of the master cylinder. How do you go about cleaning the internal workings of the master cylinder? Anyone ever had any similar issues?

Thanks in advance for any input.

 

You should be able to buy a re-build kit.

 

The company I bought it from said they got it from a different company. Neither can seem to find the proper rebuilt kit. I'm afraid that if I buy one I'll end up with the wrong one. Very frustrating!

 

If what you have is aftermarket, then finding the right rebuild kit will likely be a problem.

Why not pickup a used "real deal" replacement and then re-build it?
There's a number of them on eBay, like this one.