Ducati Monster Forum

So today while riding somewhat spirited the bike started to slow down mid turn.  I was dropping gears and heading for the side of the road when the rear wheel locked up.  I get off the bike and there is a ton of smoke pouring off my rear brake.  I mean a TON of smoke.  I had no choice but to hit it with a water bottle as there were tiny little flames licking up off the pads.  Needless to say the bike was stuck in the lane and could not be pushed, shoved or dragged out of it.  I walked it to the side of the road using the kickstand.

The reservoir was smoking hot as were the lines.  I poured water on it, waited 20 minutes and broke out the tool kit.  I finally got the reservoir cap off and used a screwdriver to pry the pads off the rotor.  End result, rotor looks pretty scored, brake pads are defiantly toasted and it is simply not working well.

Been riding 34 years.  Did not drag the brake during the ride but used it to set the suspension upon entrance to turns.  I have had well over 20 motorcycles through 600k of riding.  This is a brand new never happened before kinda thing.......

Had to add,  Stock rear brakes 5200 miles on the bike.  


Thoughts?

Have you made any adjustment in the pedal? It sounds like the fluid return port in the master got blocked.

Or install rear sets without adjusting free play?

If not, this is a warranty issue.  Either way, speak to the dealer.  New pads free play and a good flush might get things working again, but caliper, rotor, pads and hoses should all be changed.

Never adjusted the foot brake nor did I install any rearsets.  About 4k ago I installed a Rizoma fluid reservoir but had no issues until yesterday.  First time anything like that has ever happened on any bike I have ever owned.

Ddan's explanation is the most likely cause, could be due to dirt too, anyway, brake wear is not warranty, a malfunction is as long as you didn't mess with it.  When the return (compensating) port is blocked, pressure builds up, brakes drag.  This creates heat, heat makes the problem worse due to expansion.  This might just be the first time things got bad enough for the brake to lock.  Opening the bleeder to reduce pressure might allow the bike to roll.

other's have had rear brakes lock up like this.

take a quick search. most had warranty work on the newer ones IIRC

Took some time this morning and checked out the rear reservoir fluid levels.  Seems my small Rizoma reservoir is only 3/4 full so I would have thought that would leave enough room for expansion.  Perhaps not.  Either way the rear disc is still straight, not warped and no grooves.  All of the magic smoke has escaped the brake pads.  The rear brake line looks undamaged but the fluid is black.  

So:  Should I replace the brake line just to be on the safe side?  Should I only half fill the reservoir?  Should I replace the Rizoma with the stock reservoir and go talk to the warranty folks?  

I've seen a high incidence of broken return springs on recent Monster rear brakes.

Perhaps?

If the bike is 2013, warranty it.

Had a similar experience with my 2012 1100Evo, but I felt it needing more throttle than it should and pulled over. I found that the free play was not adjusted correctly. Adjusted it and have not had a problem since.

A while after that happened, I installed DucaBike rear sets for more bling, adjusted it correctly, and have not had a problem with those either. BTW, it has the Rizoma reservoir also.

As an aside, the DucaBike rearsets do not provide for a return spring, so I made my own. Don't know if the spring was necessary, but I wanted one less thing to worry about.

 [thumbsup]

Same thing happened to my friends 2012 Monster Evo

Return spring is good, fluid level not to high in reservoir, confused.....  Either way upon further inspection the rear disc is purple, I suspect it needs to be replaced.  Likely the line as well.  Off to warranty land......

Dropped it off for warranty today  :(  Left the house for the shop to put on a tire and the rear brake was fine.  Bike was rolling, within one mile the rear locked up again.  This time with zero use.....  Checked the return spring all was fine.  checked the reservoir, fluid level at 1/3rd.  Parts?  Smoking hot.

The odd thing is after it happened the first time I rode 30 miles home after it cooled off.  This time zero brake use and boom, locked.

One thing I did find odd is that the screw to the brake light switch was extended pretty far out.  It is a confusing issue.

Either way the shop said it is under waranty. they will let me know if I can toss a few bucks at an upgrade to better pads and a Galfer wave rotor along the way.  All is happy in Duc land even though my baby is sleeping in another mans garage for a couple of days  [thumbsup]

Ding Ding Ding we have a winner.

Locknut AWOL, yes?

this all seems to be a problem for new monsters ....but replace your brake fluid every 2-3 years on old ones as they absorb water which can cause similar problems

There is only one lock nut on the switch post.  It was loose and I suspect that every time I used the brake that post backed out a bit. Eventually acting like I was dragging the brake.  Needless to say it will be getting some Loctite when I get her back.

dont use locktite on that

just tighten it up to the proper tq

Like the factory should have?   ;D   

I can see what you are saying though.  Without something to grip the post locktite would force me to remove the pedal every time I needed to make an adjustment.  I spend a fair bit of time checking bolts before rides and it will be the last time I don't check that one!

I am actually kinda happy to have figured it out.  Maybe a hassle but it feels like a bit of a win  [thumbsup]

our bikes vibrate a lot

tends to back things out even if properly tq'd
ask me how i know

but locktite where it shouldn't or needn't be makes any adjustments or disassembly/service later a pain and in many cases can lead to broken parts/stripped bolts/etc

Hmm? Wouldn't the brake light have been on constant, or am I misunderstanding? If it was indeed on constant, being rear ended was immanent.

And ditto re ixnaying the locktite for that location.

The switch activates when you press the brake pedal because the post comes away from the switch.  It came on as I used the front brake and came on when I used the rear.  Right up until it got tight.  ;)    As loctight is ill advised I will add a second nut so that I can tighten the two nuts against each other.  At least then I will see the post moving up since the nut is not sliding down.

It will be a normal part of my normal pre-flight inspection from now on.  Although, I am still somewhat amazed it worked loose, every time I was using the brake it loosened up just a bit until it finally drug enough to toast it.


Not sure that made any sense. :-\

Forgive me, but I am still confused. It has been a while since I have looked at a stock rear brake setup, but the principles are usually the same.

Seems to me a brake switch that has moved out of adjustment, as you describe, would have had to reposition to an increased extension in order to affect the pedal position, and doing so would have had to exert a fair degree of torque to displace the pedal.

Normal procedure is to set the pedal position/free play to spec via the adjuster screw. If the pedal free play can not be set to spec, then the mc rod length would be the next adjust point.

Of course all of this is crap if I have totally misunderstood your problem description?

The adjuster that handles free play (and the stoplight switch) worked it's way up out of the hole on the pedal.  It reduced free play.  I did not notice it right away as I barely use the rear but after slamming a few backroads hard enough to drag a little rear brake the free play went away.  End result was light brake drag until overheating and fluid expansion slamming the brakes tight.  IMO I should have figured it out the first time  :-[ 

Gotcha now.  :)

The rear brake disc, pads and hoses were covered by warranty.  Duc must be aware of the issue and they are took care of it.  Luckily I got the bike back today as they shipped the parts right before the famous Italian vacation.  Whew dodged a bullet on that one!

Brake wear is not covered by warranty, brake defect is.

Luckily the dealer decided that the adjuster should not have backed out and they replaced everything for me at no charge.

Pretty cool  [thumbsup]

i had my bike at the shop over the weekend for a new pair of shoes.  while in, the tech noticed air in the rear brake lines - i'd noticed more pedal travel then normal, but the brake still worked and i typically only use it to set myself up in the corners or when stopped as well, so i never really thought anything of it.  anyway, moral of the story is the service manager told me he'd have covered bleeding it under warranty if it hadn't just expired. i suspect he was just blowing smoke up my ass, but i was surprised none the less...