Technical braking issues..

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Technical braking issues..

arc

this is where i stand
Joined
Oct 8, 2003
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Been having some problems with my brakes. I run red dot 6 groove discs and fast road pads, they're about 18months old and i had new shoes done around 12months ago.

My pedal has felt rather odd, so got the fluid changed. I didn't have time to do this myself, nor the desire to prat about trying to get the air out.. so let my mate at the garage do it. My old fluid came out black, so yeah - it was a bit dead!

Anyway, the reason for the fluid change was that i was getting massive brake fade, and spongey pedal. If i brake gently from a high speed, the pedal would go further down, but in stages - ending up nearly on the floor. I assumed it was just the fluid boiling, and that new fluid would fix this. It hasn't. The pedal feels firmer for the new fluid, but i can still make the brakes fade and the pedal move in stages. If i let go of the pedal when this is happeng and reapply the brakes, they'll be ok - and the pedal will be back at where it was before - but then i can make them fade again.
 
Fluid passsing a seal, I think.

Brake fade, as I understand it, and I have visited this area, is when the pedal is firm, just nothing happens.

The pad material gets to such a temperature that it does not grip the disc.

At about the time this happens, the caliper gets so hot that the brake fluid in the caliper boils. This produces bubbles in the fluid leading to a soggy pedal.

As yours comes back if you release and reapply, that is not fade.

Check the rears are still properly adjusted. As they bed in they loose their adjustment and you are pushing them a long way to reach the drum, hence the increased stroke of the pedal.

Cheers

D
 
I agree with Rallcinq, Fade only usually occurs when you've glazed the surface of the pads (due to serious ass thrashing usually!).

sounds like a faulty master cylinder/Vacuum servo.

you should get it tested before driving it anywhere mate... beleive me, i've had a cylinder go on me while driving, and
A: it nearly killed me
B: It scared the bejesus outta me...

cheers
 
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