how to fix brake fading????

[JBplays]

The rear brakes on my 04 450r start fading about half way through an XC race. I was wondering if maybe somebody could point me in the right direction...

I've checked the usual culprits and cant seem to figure out what the problem is..

rotor is straight
axle bearings are good
bled and replaced the fluid with Castrol SRF racing brake fluid
replaced the pads with new OEM pads

The brakes work fine for about 30mins - 1hr and then I lose brakes until they cool down.
I admit I am bad about riding the rear pedal. But I used to ride the brakes on my yamaha, and never had this issue.

I was wondering if maybe rebuilding the caliper and master cyl might help. Or one might be the problem...?

Anybody got any suggestions??

[Scro]

Jeff, make sure you are using Dot4 fluid. Dot3 can overheat and start to boil. Steel-braided brake lines will also help tremendously with brake fade. When the stock rubber line heats up, it expands, resulting in brake fade.

[JBplays]

Thanks Dustin!

I'll try a braided line. But I dont think that's gonna solve my problem. It feel like something more internal...?

And I switched to this Castrol SRP fluid. It has the highest wet boiling point of any Dot 4 fluid you can buy. It's what Borich says he uses...?? The cheapest I could find it was $60/liter!!!! :huh
LOL!! And it still didn't solve the problem...

But check out the specs on this stuff:

Castrol SRF Specifications:
DOT Rating - 4
Dry Boiling Point - 590°F
Wet Boiling Point - 518°F
Compatible with other fluids - Yes
Container - 33.8 fluid ounce (1 liter) plastic bottles

518 degrees wet boiling point is about 150 degrees more than most dot 4 fluids...

[Jim417mx]

braided lines!!! you will not regret them! Just make sure you bleed them properly, some times they are a P.I.T.A to get all the air out.