Rear brake smoking, locking

[paradisecity]

The bike is back in the garage, trying to decide what/where to take it.

The rear brake is now seeming to catch or something.  after a few minutes of constant riding the bike will still decelerate at full throttle because the back is rubbing I guess?  Awful smell to it as well as a lot of smoke coming off the brake unit/rotor.  It locks to the point where the bike will not move or even roll.  After waiting a few minutes it is cool enough to move again.  This happened a couple times.  I didn't notice the smoke until the last time.

[EEL]

What kind of bike? I heard of something like this happening with someone elses S*R. Forgot that person's name though. I think his bike actually caught on fire.

[Ontario_Monster]

Had a similar issue on my M620, check the adjustment nut, apparently they will rattle and move if they aren't properly set.  Not something I was aware of ended up costing me a the whole setup (actually the shop paid as thier guy had failed to correctly lock it down)  still was without a bike for 2 weeks waiting on parts.  I always check it now.

Cheers

 

[somegirl]

What kind of bike? I heard of something like this happening with someone elses S*R. Forgot that person's name though. I think his bike actually caught on fire.

Yes, that was someguy's S4R and it did catch on fire.

[Slide Panda]

Before you take it to a shop, there's a few things you can check out.

I had an issue with my 620 where a pad got hung up on the guide pin in the caliper and was rubbing on the rotor.  It got so hot that it actually blew apart the brake line.  There was so much heat in the rotor, when I finally touched the brake lever and the piston made contact with the pad - the heat dumped into the fluid locking up the caliper and very shortly boiling the fluid enough to bust the line from this banjo end. 

So based on what I learned:
Remove you pads and the guide pin.  IF the pin is dirty, gunky, rough (and it probably is)  take some steel wool or similar to it and remove the surface goop.  That goop can cause the pad to not move freely and be brushed out of the way as it would normally. 

While doing that, inspect you pads for signs of them wearing at an angle.  If they are, they need to be replaced.

I'm going to wager that you need new pads based on your description, and probably a new rotor.  I know my rear rotor was TOAST after my incident.. since it was white hot.   Also I'm betting that when you get that pin out, it's going to be rough and black as opposed to the smooth silver it was at one time.

[Speeddog]

This issue is *typically* caused by fitment of rearsets, and not adjusting the brake lever/mechanism so that there is freeplay in the pedal.
Or, just improper adjustment of the brake, such that there is no freeplay.

If the piston in the master cylinder is not allowed to retract fully, it covers over the bleed port.
This effectively seals the system, and braking heat causes the fluid to expand, but since it can't escape to the reservoir, it clamps the pads harder.
So more heat, more clamping, until you notice something's wrong or the brake line or caliper seal fail.

[Howie]

Check that you have sufficient free play at the lever.   You want 1.5 - 2mm

Inspect brake pads, since they probably overheated.

Make sure the caliper is in good working order, no leaks, pistons move easily in bores.  If there was enough heat the seals may have cooked.

If there was enough heat to destroy the caliper seals the master has probably been affected too.

Flush brake fluid, go for a ride.  Carry a wrench to fit the bleeder, some hose and a container with you.  If the brake binds again, open the bleeder, let some fluid out and close.  Bind gone?  Either you need more free play or your master is bad.  Bind not gone?  Caliper or brake pads are sticking.

[paradisecity]

I guess the big question is, should I take it back to the guy who did the work initially?  I think everyone here knows whats been going on.  I have a warranty based on proper install of parts, but Im starting to worry about the longevity of my bike as well as my safety here.

It seems that this thread below was actually two problems together- one for the rear brake system and one for the grounding cable:

http://ducatimonsterforum.org/index.php?topic=4278.0

[Popeye the Sailor]

Take it back to the guy. If nothing else, if problems keep cropping up and you need to take some sort of legal action, you have proof that 1)the bike had issues and 2)said mechanic was made aware of those issues and asked to rectify them. If you just fix it yourself, it's like it never happens.

And to be the voice of pessimism....I wouldn't be surprised if there were more problems, and if so, you may need to consider legal action. They guy was s'posed to build you a bike, not a pretty paperweight, and right now with the brake problem, it's downright dangerous.




Keep in mind that last bit is coming from the guy who *had* the same porblem and had his bike catch on fire. Yeah.

[Popeye the Sailor]

The rear brake is now seeming to catch or something.  after a few minutes of constant riding the bike will still decelerate at full throttle because the back is rubbing I guess?  Awful smell to it as well as a lot of smoke coming off the brake unit/rotor.  It locks to the point where the bike will not move or even roll.  After waiting a few minutes it is cool enough to move again.  This happened a couple times. I didn't notice the smoke until the last time.

Btw....when your bike has a serious issue.....stop riding it. I had the same one...once and I very nearly got killed. I cn't imagine why you would ride it further.

[Howie]

Someguy's bike is not the only one that had a rear brake go up in flames.  I know someone who had it happen twice.

[paradisecity]

I'm not riding it anymore.  I got it to the closest safe place that I could and parked it and it is still there.

The guy who let me put it in his garage says he thinks it is leaking a little gas too.  Awesome.  Real impressed with the work done.