brakes and rain

[rybes]

mornin all

got caught in a rain storm yesty. not a prob ill jus get wet. that was until i went to pull the front brake on and it went straight to the bar without any real brakin assitance.
jus gone out to it to see and it feels as if theres no fluid in there. any ideas what mightve happened ? cos i aint gotta clue

cheers 

[metalguru]

How is the fluid level in the master cylinder?
Blown brake pipe...Look for leaks.
Worn out pads, are they down to the metal? (Score marks on the disc).
If those ok, suspect mastercylinder seals gone.(The handlebar one).

[rybes]

fluid levels fine, brake lines are fine, pads are good too. master cylinder seals got replaced bout a month or so ago. jus fitted some tockico 6 pots on and currently bleedin em to see what happens

[FoothillRyder]

I just cannot imagine how this has any connection with the rain. 

[metalguru]

I just cannot imagine how this has any connection with the rain. 

Somewhat puzzled about the rain!!
Was the master cylinder honed or cleaned up before replacing seals?
Have known new seals to leak when they hit the un-worn/unswept part of the bore.

[Nick Calne]

Maybe bad fluid with water in it? I guess....

More critically i trust you are ok. Did you write-off your undies or were you not going fast?

[rybes]

well i dont know whats goin on with em. bled em up yesterday and can no longer get air out of any part of the system. tried a new set of calipers, had the lever tied back all night last night and still no brakes  .
which means im now stuffed as ive tried everythin i know and still cant get a lever.
so far i have tried :
pumpin the lever and releasin the nipple, still no brakes
pressure bleedin from the top, still no brakes
pressure bleedin from the bottom, still no brakes
usin a vacuum pump to draw fluid throo the bleed nipple, still no brakes
rebuilt master cylinder (unhoned cos i aint got a tool for it), still no brakes
another set of calipers, guess what ? .........still no brakes

im now at a point where im thinkin of rippin meself off and takin  it to a dealer. 

[London_Phil]

If you still have flexible hoses, not braided, perhaps you could try clamping one caliper off, and bleed the other, to see if you can isolate the fault. Its a closed system,  so either there is a fault in one or more component parts , or you have air.
It can be very frustrating.
Some years ago my sister bought a car, and the front brakes would only work for about 1000miles if new pads fitted, turned out a locating pin had sheared in one of the callipers, which meant that movement of pad was restricted to just a few millimetres, took a lot of finding, and only when we finally clamped off the brakes one by one to find where the fault was.

[Bixxer Bob]

Phil's on the right track, you have to break it down into stages until you find the bit not working.  You've done well so far, establishing that there are no leaks, and no air in the system and the calipers are unlikely to be the problem as you've changed them.

Go out to the bike and pull the lever on and tie it back.  Have the pads moved?  If they have can you prise them back with a screwdriver or similar (carefully, don't damage anything obviously).  If the pads haven't moved, or if they have but can be prised back, then the prob is in the master cylinder.  I don't know without seeing them if the seal can be fitted the wrong way round but it's an idea.  Also look at the valve that draws fluid from the reservoir to make sure it's not letting fluid past.

Since you have fluid moving through when you bleed them and no leaks it can't really be anywhere else.

[metalguru]

BB is right there, as had similar before especially with pattern kits for the master cylinder.
The main seal can swell slightly with brake fluid and can cover the inlet port under normal operation but if pumped fluid is involved, will pass through the port. The brake lever not returning fully or if an aftermarket one is used then it can stop the plunger from returning fully, again covering the port.
Sometimes if the cylinder isn't honed, when the new seal passes over the unworn part of the bore, it can get damaged by the unused bore being rough.
I believe Kawasaki master cylinders are similar.

[rybes]

cant block off a hose unfortuantly cos i got braided lines on it. later on today im goin to try one line from the master cylinder and a loop over line from caliper to caliper. ive got it in me head the airs in the master cylinder. so im thinhkin if i take out the double banjo bolt and replace it with a single one theres less places for the air to get trapped. if they dont work ill be lookin at the master cylinder.
when i replaced the cylinder seals, genuine not oe. i still had no real improvement in the feel of the lever. so i thought that perhaps it wernt that what was causin the problems. hopefully today ill suss it

[rybes]

yesterday saw me remove one brake line from the master cylinder and replace it with a caliper to caliper line, i tied up the lever last night and guess what ? ive got a brake lever  .
so im guessin that i jus couldnt get the air out of the double banjo bolt as once id swapped it down to a single line i bled it up in not time 
now its just a case of beddin in these new pads i got n i should finally have decent brakes 

[Bixxer Bob]

Well done mate, logic and perserverance are the keys eh?

[London_Phil]

Nice one.  Glad you got there in the end, makes it all the more satisfying..

[rybes]

cheers all  didnt last long tho. by the end of the dat the lever was back at the bar. so ive bled it again n got a bit more air out. i think this is goin t be a long slow process