Front Brakes Locking Up

[kyle_dewald]

I recently purchased an XB9R and the front rotor was warped so I ordered it. In the mean time, the front brakes will lock up while driving and when I say lock up, I mean pull a stoppie lock up. I replaced the rotor and the brake pads. I noticed that one of the piston in the calliper was stuck. Thought it may be fine, but I got it all back together and did the same thing. Still locking up so I ordered the front caliper, which came with new pads as well. Rode if around for quite a bit, no problem......... then it locked up. The only thing that has changed from when I was working properly, is that my boss dropped the bike and I had to change the brake lever. What is the problem? I've over sunk $500 into the front brakes and I still have the same damn problem..... I need help

[ophawk]

Make sure that the fluid in the reservoir is not all the way to the top, as the fluid warms up it expands and has to go somewhere, pushing the pads out. Be sure that the system is bled correctly also, air in the caliper will expand as you ride from the heat produced, and can possibly cause this.

Later

[theoctopus]

+1 to ophawk

You need to make sure your brake fluid is taken care of appropriately first and foremost.

Failing that, I would start looking at the mechanics of your brake lever and the condition of your brake line.

[ophawk]

You may also have an issue with that brake lever. I found the other post
Front brake lockup
Later

[kyle_dewald]

Thanks, I ordered pazzo racing levers to replace the ones my boss messe up and that may be it. The clutch lever wasn't the right one and so I'm sure the brake wasn't either. I haven't been able to get anyone to respond to emails or calls... May have to do a chargeback

[stopie20]

I would replace the fluid in the brake system if the bike is new to you.

Some one could have used the wrong fluid meaning it is not a high temp fluid this would cause the fluid to expand more than the system is built to tolerate, and since your brake lines are braided steel this is espically dangerous.

[rndrkeagle]

+1 what Ophawk said.. I was the one with the issues in the thread he pointed to. The correct fluid and ensuring there is no air in the system are both very important things to check for proper operation of your brakes, but in the end, if your master cylinder piston is allowed to return all the way to the circlip that holds it in, then any pressure that builds up in the line (air or otherwise) should be able to clear to the reservoir through the relief vent. Even the best brake fluids will expand as they warm and this relief vent in the master cyl assembly is there to let that clear and not engage the brakes. In my case, it was literally 1/32 of an inch, hardly detectable even when comparing the two side by side. (It was like that find the differences game in the Sunday paper comics section). Filing the nub down on the lever fixed the problem and I haven't had any issues since (that was a year ago).

Best of luck.
-Wade

[Stevenc150]

The clutch lever wasn't the right one and so I'm sure the brake wasn't either.

That's you're problem. To confirm, take the brake lever off and go for a ride - being careful of course.

[kyle_dewald]

that was it, took the lever off and it looked identical to the previous, but it was for the 1125R not mine. fixed the problem.
Thanks for all your help