I have a problem with the front brakes on my RK and I’m not sure if it’s a master cylinder issue. When I squeeze the front brake the bike stops fine but the small piston that pushes the brake lever back to its normal position moves at a snail’s pace. Once I squeeze the lever I have to use my hand to push the lever back and hold it until the piston finally moves out and touches the lever. If I don’t do this my brake light stays on. The brake light switch is fine so that isn’t the problem. I took apart the switch housing and verified that the piston isn’t moving as it should. Is the piston motion controlled by the master cylinder or is there a spring or something else that pushes it out? If the problem is the master cylinder would a rebuild kit fix the issue? Also is the rebuild kit easy to install or it fairly complicated?

Thanks for any advice!

 

Check to see if the nut that holds the brake lever in place isn't to tight. What year RK are we talking about here?

 

Shortride - It's an 05 RK Custom. There isn't a nut that holds the lever in place. The lever is held in place with a pin and retaining ring. The lever moves freely.

 

There's a spring that sits partially inside the piston. Take apart the master cyclinder and check the o-ring and rubber cup. Clean the piston. Dirt could make the piston stick and not return quickly.