View Full Version : Front Brake Locked Up

06-04-2014, 10:46 PM
For starters I've got a 2002 Buell Blast. Only minor problems in the past, none with my brakes.

Here's the problem. Yesterday I noticed my front brake lever felt stiffer than normal, it was a hell of a lot tougher to pull and it activated the brake after about a millimeter of pulling. I didn't think much of it (bad decision #1.) Same situation this morning, no problems though.
Then after work today on my way home after about my fourth stop sign, I felt my front brake lock up, like it just got stuck. Luckily I was only about 40ft from my driveway and I super rev'd that f*ckr the rest of the way.
I looked at the brake pad, yep it's clamped down. Spit on the disc, and it sizzled like a frying pan.
Any advice? I have no idea where to start.

06-04-2014, 10:54 PM
Your scenario has happened to me. You might check that there is a slight gap between the master cylinder plunger and the brake lever while the brakes are not applied. If there isn't your plunger might be getting applied as you ride. To fix it, I ground the lever to achieve the slight gap about 1/16"

06-04-2014, 11:04 PM
Thanks for the reply. I am not very familiar with brakes, especially in motorcycles. I'll take note of that though. and maybe get to work on it tomorrow evening.

UPDATE: after letting my bike sit for about 45 minutes, I went out too see if it would roll. It rolled. The brakes are no longer locked. There was less pressure behind the brake lever. There is however, a light scraping noise coming from the front brake like it's still slightly engaged.

06-04-2014, 11:15 PM
Release the pressure on the caliper(pull the brake lever in and hold it and turn the bleeder screw,let the fluid shoot out,and tightin the bleeder screw,then check the gap between your lever and plunger.some aftermarket levers will need to be filed down slightly to work.When its hot out,the fluid swells and when the gap at the lever is not correct the brakes will lock up

06-04-2014, 11:50 PM
ztied, you mentioned the possibility of the lever maybe being too close to the plunger. I don't have aftermarket levers, and there is about a centimeter before the lever "clicks" the plunger. (is the click it actually engaging, or could it be before the click?) I can't see the plunger mechanism itself behind the rubber cover. I'll put up a pic.

http://i.imgur.com/aMwvpq7.jpg (http://imgur.com/aMwvpq7)

06-05-2014, 12:30 PM
I am not sure what the correct gap would be. It should have just a little space inbetween the plunger and lever. Note where the plunger touches the lever,and pull the lever off,and file just a little off of that spot.It shouldn`t take much.
The locking up problem,usually happens on the real hot days,When my bike had the problem,I carried a socket with me to releave the brake pressure if it locked up,until I got the lever loose enough.There may be other fixes but this worked for me.

06-05-2014, 11:58 PM
The "click" you hear is the front brake switch I imagine ...

Sounds like the return port in your master cylinder is plugged up ... it happens sometimes ... just gotta open the reservoir and poke out the crap with a paperclip or something ... happened to me on my r6 about 2 or 3 months ago ... bleeding the brakes won't really help that ..

06-06-2014, 01:38 AM
No the bleeding just unlocks the caliper so you can move the bike

06-06-2014, 09:32 PM
Yep that's right ... cracking the bleed screw will relieve the pressure to let you move it, but if you don't clean out that return port the problem is going to come right back next time you apply your brakes when you ride it ...

06-07-2014, 02:22 AM
Yes i agree my solution just gets you home

06-10-2014, 12:38 PM
I think yall are right. I eliminated the possibilities of bad break fluid, or lever problems. I noticed while flushing the brake fluid that there were a few little floaters which I removed with a Q-tip. I also noticed the two holes in the master cylinder, one would open when I applied the brakes, and the other did nothing. I bled off some pressure to get it home yesterday, so I guess that means it's not a stuck caliper piston. Once the rain lets up down here I'll try clearing that return hole with some guitar string or somthing. Thanks for the help, hopefully next time I will have good news.