Front Brake problems

[loony888]

love to see dribbles of information when you're trying to help someone, for make the beast with two backss sake vince! tell us you have changed levers and pads and they're useed, and you didn't mark what place they were in on the other bike and it was doing it before you changed the pads over etc. etc.
are those fancy levers set correctly, the old type with the screw in the end were notorious for blocking the bypass port in the m/cyl when wound in too far causing a build up in pressure and locked brakes. yeah yeah, i know, you know what you're doing and it can't be that but your brake fluid theory is bogus. there's no way brake fluid will expand when it gets hot, it's designed to do exactly the opposite and being a serious safety item (brakes!) it just wouldn't be acceptable to allow that under any circumstances.

paul.

[DUCMONROB]

love to see dribbles of information when you're trying to help someone, for make the beast with two backss sake vince! tell us you have changed levers and pads and they're useed, and you didn't mark what place they were in on the other bike and it was doing it before you changed the pads over etc. etc.
are those fancy levers set correctly, the old type with the screw in the end were notorious for blocking the bypass port in the m/cyl when wound in too far causing a build up in pressure and locked brakes. yeah yeah, i know, you know what you're doing and it can't be that but your brake fluid theory is bogus. there's no way brake fluid will expand when it gets hot, it's designed to do exactly the opposite and being a serious safety item (brakes!) it just wouldn't be acceptable to allow that under any circumstances.

paul.

+1

[Dockstrada]

Ok some more information dribble.

After the calipers cool down, Hey presto it all comes good. How do you explain that, i have no idea other than the expanding and contracting of something 

spoke to somdumguy today he say "danielson"  in some cases there is small air bubbles trapped in the calipers in areas higher that the bleeder or brake line connection,which can cause this problem.

The most common way of getting air into your system is pushing the pistons back to fast , this mixes small air bubbles in with the fluid as it returns to the reservoir ,When you pump your leaver to take up the slack after fitting new pads you send it back down the line with the fluid. 

 

[loony888]

well bleed your brakes properly then!

[Dockstrada]

well bleed your brakes properly then!

Going to try some Motul 660 factory line .

[loony888]

what's the DOT rating of that?
the higher the dot the faster it absorbs moisture and the more often you will need t replace it.


paul.

[Dockstrada]

what's the DOT rating of that?
the higher the dot the faster it absorbs moisture and the more often you will need t replace it.


paul.

Im going for DOT4

RBF660 FACTORY LINE
 
100% Synthetic Racing Fluid – DOT4
Very high boiling point: 325℃/617°F
Very high wet boiling point: 204℃/400°F.

SPECIFICATIONS
 
Feature 100% Synthetic Racing Fluid. Polyglycol bases.
 
SAE/DOT Standard FMVSS 116 DOT 4/ SAE J1703 & J1704
 
Specification ISO 4925
 
http://www.motul.com.au/product_line_up/fork_brake_others/others03.html

[Nickati]

I still can't see it being the issue

Hey why you want brakes anyway, they just get in the way of speed 

[brad black]

after a session put a piece of clear hose on a bleeder, hold it vertically and crack the bleeder.  fluid comes out quickly = fluid pressurisation problem.  it will run fluid out slowly due to the level difference, but if it shoots up the tube it's pressurising.  close the bleeder and try moving the bike too.  make sure nothing is blocking the piston from coming as far as as it would without a lever fitted.  the only way it can pressurise if is the compensating port is blocked.

[Nickati]

One question, did just changing the pads fix the original problem ?

[loony888]

after a session put a piece of clear hose on a bleeder, hold it vertically and crack the bleeder.  fluid comes out quickly = fluid pressurisation problem.  it will run fluid out slowly due to the level difference, but if it shoots up the tube it's pressurising.  close the bleeder and try moving the bike too.  make sure nothing is blocking the piston from coming as far as as it would without a lever fitted.  the only way it can pressurise if is the compensating port is blocked.

top advice, i suspected the levers not being set right as the culprit when vince posted the pic of them, excellent way to diagnose it brad.

paul.

[Nickati]

One question, did just changing the pads fix the original problem ?

Or was something else done at the same time ?
Or did all this start after the levers were fitted ?

[Dockstrada]

Or was something else done at the same time ?
Or did all this start after the levers were fitted ?

Started with in a few track days and got worse still as a standard bike.Its only when i fitted the last set of pads that it is so bad that the front wheel need a fair amount of force to get it to turn.basically i need one hand to turn the wheel to fit the tire warmers.But as stated before after a short while it all sorta goes to back normal, just a little drag.

Some extra dribble, cuz i know how much Loony hates it.

The rotors are blue/black not on the ends just on the faces.I have also noticed that some of the racer guys have the same problem ,just a little less than mine.waiting for Craig McMartin to give me a buzz with some info.

BR Vince

[Dockstrada]

Just found this.

http://174.143.221.140/ME2/Audiences/dirmod.asp?sid=&nm=&type=news&mod=News&mid=9A02E3B96F2A415ABC72CB5F516B4C10&tier=3&nid=7A529F8E7D7748A992DC1F09C716CA00&AudID=7D8998E6B4B64029B8320B216F4F3861

[signora monster]

My old Kawasaki is a bit like this. Could it be wheel bearings? 
Kaz.