Title says it all. I got a pretty good scare yesterday afternoon leaving
from work. I was 30 sec. from merging on the highway when my front brakes locked up on me. I began feeling some resistance but failed to realise right away it was the brakes. I originally believed it was an engine issue since I’ve been playing a lot with carb setups lately.
So, like an idiot, you feel resistance, what do you do? Open throttle to see if it’ll free itself, or, once cleared a certain RPM, the carbs will settle. In the meantime, the front brakes are locked, and the discs are turning blue. The hotter they become, the more the brakes lock.

That’s when I realised, my front brakes are locked! So, let go of throttle only to have the bike come to a jerking halt, almost falling with it.
Now, the problem is I’m in the middle of a 70km/h(45mi) road, and, I need to get the bike out of the way. While traffic is swerving around me, I start the bike up again, to move it to the side of the road. What a job. Just to move this pig with locked up front end about 5-6’, was no walk in the park.
Kept wanting to fall with the front tire sliding.

This is my new Brembo M/C installed about 2 weeks ago, but never really had a chance to test/ride it. I guess dirt particle clogged return valve forcing the calipers to remain locked. I managed to purge the master on the side of the road and release pressure. Let the front brakes cool off, played with the front brakes a few times to be sure they don’t lock up again. Road the pig back home just using rear brakes to play safe.

I guess I’m lucky in a sense since this happened just before getting on the highway. I hope I didn’t warp my discs in the process. I didn’t chance braking the front end to check before I flush and bleed the brakes again.

Hmmmm I smell fowl play here since Mikstr helped me that day. I had to leave him in the garage for about 15-20mins while I watched over my kids....;O)

 

Possible moisture (or beer) in the system?

The brake system.

 

Have you thought that maybe your "pig" had a porcine flu? lol

 

Wow, thats nuts. Very glad to hear you survived to tell about it. I thought stuff like that only happened to me.

If it was me it woulda been in the 30* rain.

In general, brake locks are caused by moisture in the lines. Once it heats up, it boils, steam expands and its a vicious cycle til they lock.

I would be skeptial of debris but anything is possible. However, how did it cause catastrophic failure and yet you "cleared it out?". That may be your foul play right there.

You should be super careful when you do the fix, dont spill any more beer in the DOT 4.

 

The problem may be the cheap Chinese lever... I recall reading that this is an infrequent but not unheard of effect brought on by some Pazzo-replica levers... seems they exert a bit of pressure on the piston, which causes the calipers to drag slightly, also causing the brake fluid to heat up and expand and, well, you know the rest......

Do a Google search...

http://www.gixxer.com/forums/showthread.php?t=335452

FWIW, I, and others, have run Chinese levers before with no problems, but this was not one of those instances.......

 

I have seen and fixed several brake lock issues.. at least two of them were due to the incorrectly manufactured lever not allowing the master cylinder piston to return completely after using the brakes.. and so with each squeeze a little less pressure is released from the caliper..neither of these bikes showed issues at the post install around the block "test" but once out on the street or track,, with many repeated uses of the brake in a short time.. the caliper locked up on the disk

 

Everyone's a comedian.....thanks for the laughs......I think ?;o)


After speaking to Mike about it, and reading his link to the Gixxer forum, once finished flushing fluids and bleeding, lever's comin off to be analyzed/fixed.

 

I was absolutely serious as usual. Joe followed-up with the same idea and that guy's serious as a heart attack.

 

I'm very glad you're OK. Great job thinking the problem through and making the bike rideable. Brakes are so reliable now that's it's perfectly reasonable to believe that the issue was related to the motor.

 

He makes Oral Roberts look like Ozzy Osbourne.

 

Well, now, I didn't say he was E.Marquez serious.

 

Ouch.......removing stick time now.......