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Discussion Starter #1
Hello all- I am a new owner of a 2008 312 1000R. upon ridding it home from the dealer I noticed the rear brake locking up at stop lights. I quickly deducted that the rear brake cylinder was getting too hot and boiling the fluid. the cylinder is only about 2 inches away from the pipe and gets hot fast. I thought once i got on the freeway it would have more airflow and be fine. after it cooled and released i got rt on the freeway and after about 2 miles @ 70mph i looked down at the rear brake and saw the caliper and brake line was on fire and the rotor was BRIGHT orange!!! i pulled over and disconnected the rear brake (after it cooled) to make it home.

My question is has anyone ever experianced this and is there something I need to check/do before I install new parts (the pipe is already thermal wrapped)?? also where can i get parts fast?
 

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Someone stuffed around with the brake master cylinder push rod. This means the plunger does not return to it's seated position to release the pressure.
MV's are notorious for having failing rear brakes, looks like someone tried to sort that problem but created another.
 

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I believe that it is more likely that the rear brake lever has been adjusted with not enough play in it.
You can adjust the rear brake lever on a 1999 - 2009 F4, and probably a Brutale, so far that it lightly holds the brake pads against the brake disc.
What happens when the pads are in light contact with the disc is that over time the resulting friction heats the pads up. This is the heat source that is gradually being transferred to your rear caliper / brake fluid.
In this scenario the heated brake fluid will expand pushing the caliper pistons and pads harder onto the brake disc.
This, in turn, will add more heat to the brake system expanding the fluids more and it continues on until the situation you found yourself in.

If I am correct here the solution is to adjust the rear brake lever position to a point where it is not applying any force to the master cylinder.
I hope that you have not rooted any parts.
 

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Discussion Starter #4
thx for your reply. Unfortunately The parts are cooked now so I can't check that. however I did Adjust the pushrod to allow for plenty of play. I did this after it locked up from sitting at the first stop light thinking it would help.
 

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Bugger, I imagine the caliper was already damaged by the time you noticed something was wrong.
Well there's heaps of parts available here on the forum, check the For Sale section, good luck with the repairs.
 

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Hmmmm...same thing happened to me while riding CAG's SPR at the Bubba track day a couple of years ago.....left me sitting in the middle of the track with a locked up rear wheel. At least I didn't crash.

The master cylinder plunger is adjustable separate of the pedal height. The only thing that that causes brake lock up from heat is mis adjusted master cylinder plunger keeping the fluid return port closed.

CAG may have some brake parts for you...pretty interchangeable amongst models.
 

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Like Ed said......misadjusted


throw another disc and pads on it and adjust the push rod correctly

it shouldn't have hurt the caliper
 
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