I was coming home from nh yesterday going about 75 front brakes just decided to lock down! Luckily i was in light traffic on the outside lane and managed to drag the bike of the highway before anyone got to close.has anyone ever experienced this before? It scared the s#@t out of me. Im going to pull the calipers the pads are good the left rotor was the one that locked.i do not want to experience this ever again should i replace calipers and rotors?
Front brakes??????????
- Thread starter MIKE R
- Start date
SANDFLEA85
Registered
your front brake "locked" at 75mph and you didnt do an endo? I find that hard to believe.Ive gotten the back tire up at only about 35mph and had to lock em up.
I agree with TIMMYdUCK
I agree with TIMMYdUCK
Sorry to hear that mate, glad you are OK and good save 
Never heared of front brakes locking up but I have had the rear brakes lock up but that was a long time ago. Think you will find that one or more pistons have seized. Take the left hand caliper off and remove brake pads, check if the pistons move freely. You can get service kits but if the pistons are pitted best to get new st. steel pistons. Also check out the disk it maybe warpped.
I am sure that the org. sponsors can help
Never heared of front brakes locking up but I have had the rear brakes lock up but that was a long time ago. Think you will find that one or more pistons have seized. Take the left hand caliper off and remove brake pads, check if the pistons move freely. You can get service kits but if the pistons are pitted best to get new st. steel pistons. Also check out the disk it maybe warpped.
I am sure that the org. sponsors can help
Are you using aftermarket levers? 
There is an underlying reason that the rotor warped and siezed up in the caliper.
It could be anything out front , you need to raise that front end up and check out everything.
It could be something major like a tweaked tube.
You do a lot of wheelies or has the bike ever been laid down ?
It could be anything out front , you need to raise that front end up and check out everything.
It could be something major like a tweaked tube.
You do a lot of wheelies or has the bike ever been laid down ?
Do you have an aftermarket master cylinder?
I think your brake system is not venting! You brake fluid gets hot or at least warms up as you ride. Your rotors drag slightly on your pads creating a little heat along with the normal brake use. This causes the fluid to heat up and expand. If the system is not venting properly through your reservor, the heated fluid will expand causing increased pressure on the pads which creates more heat. This continues until the breaks get so tight the wheel locks or it brings you to a complete stop.
That little rubber piece in the top of your brake fluid reservor is designed to take care of this expansion. Check that puppy out along with the little groves in the lid to make sure your system can vent properly.
Check with BrendanP, he has first hand experience with this issue!
I think your brake system is not venting! You brake fluid gets hot or at least warms up as you ride. Your rotors drag slightly on your pads creating a little heat along with the normal brake use. This causes the fluid to heat up and expand. If the system is not venting properly through your reservor, the heated fluid will expand causing increased pressure on the pads which creates more heat. This continues until the breaks get so tight the wheel locks or it brings you to a complete stop.
That little rubber piece in the top of your brake fluid reservor is designed to take care of this expansion. Check that puppy out along with the little groves in the lid to make sure your system can vent properly.
Check with BrendanP, he has first hand experience with this issue!
proud dad
Registered
Left side only? That sounds like the crossover brake line is colapsing internal
My guess:
The brake system has been woefully neglected.. the fluid is saturated (moisture) and likely some corrosion in the system..
corrosion starts to hang pistons and drag pads a bit
pads start to get hot
heat goes into pistons
then into the fluid causing the moisture to boil
the system builds pressure and the easiest to move pistons start to move out
more friction, more heat, more boil and this leads to pressure system wide and the brakes self apply...
time to tear the system ALL apart (all masters, rears and clutch as well)
As this is about the easiest part of the bike to maintain, I would bet the rest of the bike is lacking also...
Wayne does hit on a point with the cross over line... this is possible but pretty rare, the internal lining of the brake line separates and then flaps shut like a heart valve, this however does not explain the solid brake lever feel.. (to check for this you pump up the brakes solid and spin check for hung brake... if hung, open bleeder on one side then the other, one side will have pressure and the other not...)
The brake system has been woefully neglected.. the fluid is saturated (moisture) and likely some corrosion in the system..
corrosion starts to hang pistons and drag pads a bit
pads start to get hot
heat goes into pistons
then into the fluid causing the moisture to boil
the system builds pressure and the easiest to move pistons start to move out
more friction, more heat, more boil and this leads to pressure system wide and the brakes self apply...
time to tear the system ALL apart (all masters, rears and clutch as well)
As this is about the easiest part of the bike to maintain, I would bet the rest of the bike is lacking also...
Wayne does hit on a point with the cross over line... this is possible but pretty rare, the internal lining of the brake line separates and then flaps shut like a heart valve, this however does not explain the solid brake lever feel.. (to check for this you pump up the brakes solid and spin check for hung brake... if hung, open bleeder on one side then the other, one side will have pressure and the other not...)
Last edited:
Note to self, properly maintain brakes!
Glad everything worked out as it did, that could have been bad. Hopefully it is something I never experience.
As for causes, I can't add to what has already been said.
Glad everything worked out as it did, that could have been bad. Hopefully it is something I never experience.
As for causes, I can't add to what has already been said.
Thanks for advice. Bike has new galfer lines pads have 2k bike only has 2,500 it has not been neglected the calipers are coming off ill do the seals pistons over if neccesary the levers are the new adjustable chromes from roaring toyz i dont think they are the problem. Its good that the season is over ill have plenty of time on my hands to fixer up. Thanks again
Similar threads
