The front brake on my Night Train gave me a lot of grief today.

While riding today, the bike seemed to lose power, I shifted down but it felt like I had jammed on the brakes. This nearly caused the other ten riders behind me to run up my arse. i pulled over to the side of the road and by the time i stopped the front wheel was locked up. The scenario of the brakes staying on and getting worse occured another three times until i managed to get home. The only way to stop it was to not use the front brake.

The solution to get home was to use a 3/8 spanner and release some of the fluid each time it happened.

So what has happened to my front brake?

 Have u had yer front wheel off recently ?

not in the last 2000 k's.

The same problem used to occur on an old KTM I once had but I never got to the root cause of the problem before I sold the bike.

As soon as the pressure is released the lever has the usual play in it. If the brakes are still hot and you pump the lever several times the pressure build-up increases and the fron brake will stay on even before you move the bike.

I'd start with a master cylinder strip down and inspection/ clean and flush system lol

Hilly, your scare'n me

Just done a quick google. Bleed port in master cyl blocked. As mentioned earlier pull apart and clean clean clean.

Or this

Here is the fix. What has happened is that the brake fluid has gotten behind the rubber seal that seals the caliper piston in the caliper.
Take the caliper off the bike and use the brake to pump the piston out of the caliper.Make sure that you keep the brake reservoir full of fluid.Any air wile pumping and it wont come out.After you have the piston out look inside and you will see a flat rubber ring inside the opening in the caliper.with a pick pry it out ( don't damage it )After it is out in the grove you will see a yellow hard substance, dried brake fluid.Use a small brass brush and get ALL of it out of the groove.You can use the rubber seal again but I recommend a new one I think Honda still sells them.Also check the piston ANY damage on the sides replace it Honda again.Put it back together making sure you lubricate ALL parts with brake fluid.DO NOT cock the piston when you put it back in.It has to go back straight, very little clearance.

anuther prob with front calipers is they have steel pistons which run in alloy housing over a few yrs use when ya on a decent ride the steel expands faster then the alloy an the piston can bind or stick ive done heaps over the yrs few my mates got alloy front calipers made with O.W.M.C on em after few runs they started to fuck up best fix was get staino sleeves fitted with staino pistons never had a prob since
few yrs back built a pretty nice evo from ground up fitted honda blackbird proportional brakes to it 20 mtrs of lines threw the frame but worked great most jap bikes got staino inserts an pistons
if ya do pull caliper down get some 1200 wet n dry an give a scuff up BUT ONLY USE DOT5 AS LUBE NOT WATER and put rubber grease on any rubber seals ect to help em not go hard in time

This happened to me last week, when replacing the levers the shop broke me brake switch inside the housing this made the calipers close and and not spring back again. Had to wait on the side of the road till it softened up, the break lever was rock hard too and the disc was squeeling a little when it happened, just had to let it cool.

Switch replacement did the trick, probably not your issue but may help others in the same boat......

 

 

all brakes on any motorbike should have there masterclyinders front & rear brake fluid keep clean   ,reflush & bleed untill clean fluid comes out the bleeder every 6 to 9 mths @least , esp dot 5 its takes  more damp/water in  & has less temp boiling point esp if its older ,     if older bike strip & clean out the caliper  & re ass with brake rubber grease only ,   (  brake fluid is not a lube for ass only for the hyd action ) ,                                                       do not risk front brake lock-up esp  ,   but rear brake as well , 

make sure also that dot 4 has not been mixed with dot-5  as this will bugger  things up,    some times you have too strip & clean , hone the brake master cylinder depends how bad it is

i said use dot5 as lube for the 1200 when rubbing maybe i should have been more specific hey then use rubbergrease
wat would you use with 1200 to rub daddyracer ?

 i wasn't realy answering  too your  post ,   just for the brakes in general , but i would rub with 1200 & a light scott pad brown  not green as too course  rub in a cross hatch pattern as like a cly bore  not across or @ 90 deg's  but a 30 deg angle from left to right piston & bore , wash out &   hot water & dry clean,   put new seal in dry then use the brake rubber grease on bore & piston & ass caliper

 i wasn't realy answering  too your  post ,   just for the brakes in general , but i would rub with 1200 & a light scott pad brown  not green as too course  rub in a cross hatch pattern as like a cly bore  not across or @ 90 deg's  but a 30 deg angle from left to right piston & bore , wash out &   hot water & dry clean,   put new seal in dry then use the brake rubber grease on bore & piston & ass caliper

There is a tiny capillary hole in the master cylinder that easily gets blocked when the brake fluid isnt fresh. This can cause your problem

 Had the same thing happen to me after fiting aftermarket levers

I went into my local dealership, (Mackay Motorcycles) and spoke to Fred behind the counter. 10 mins later I walked out with a new Master cylinder complete with lever for $145.00. The old cylinder was corroded anyway. This fixed the problem. I had to remove the caliper and brake line from the bike (not from the master cylinder) and hang them from the garage door. This is because the air would not bleed out of the line. That was until the caliper and lines were placed above the master cylinder. This pushed the air up and out after many minutes of pumping the brake lever. I now have a firm front brake that don't lock on.

  Thanks to all those that posted.

I went into my local dealership, (Mackay Motorcycles) and spoke to Fred behind the counter. 10 mins later I walked out with a new Master cylinder complete with lever for $145.00. The old cylinder was corroded anyway. This fixed the problem. I had to remove the caliper and brake line from the bike (not from the master cylinder) and hang them from the garage door. This is because the air would not bleed out of the line. That was until the caliper and lines were placed above the master cylinder. This pushed the air up and out after many minutes of pumping the brake lever. I now have a firm front brake that don't lock on.

  Thanks to all those that posted.

I went into my local dealership, (Mackay Motorcycles) and spoke to Fred behind the counter. 10 mins later I walked out with a new Master cylinder complete with lever for $145.00. The old cylinder was corroded anyway. This fixed the problem. I had to remove the caliper and brake line from the bike (not from the master cylinder) and hang them from the garage door. This is because the air would not bleed out of the line. That was until the caliper and lines were placed above the master cylinder. This pushed the air up and out after many minutes of pumping the brake lever. I now have a firm front brake that don't lock on.

  Thanks to all those that posted.

My 2007 FXDWG started doing this today as well.  Stopped off at the dealer and the first thing that the mechanic states is "there's yourproblem, its not a genuine master cylinder / front brake".  The next solution was to replace the entire master cylinder, stated it would be a blocked pressure return in the master cylinder. I asked about just replacing the seals and give it a clean thinking that'd be the easiest option. Apparently finding a seal kit could be an issue along with their hourly rate.  For a genuine HD chrome front brake setup will leave me about $500 poorer.  Think i'll be taking it apart to see what make it is and if i can get seals etc for it and doingit myself.  Until then i'll be putting the original one back on.

 it would not hurt too hone & clean the master cyl out , but make  sure the lid can breathe or vent as when you screw the lid down you can squash the small vent off , e.g. help late model Aprilia RSV- 1000 formula extreame   out  @ races pit crew found same problem with the brakes binding   could not push pads back in caliper when hot after racing when changing tyre's etc  brakes were holding bike up @ speed luckly only 4 to 5 lap races not 7 or 10 lap's , these are late model gold brembo's as e.g. . put a bigger breather in & fix the problem ,  i would check this  1st  as the rubber squashes out when you screw the cap down , other teams on the same model were having the same problem,     racing bring much problems forward