L/H rear brake fading

[Taffy]

i have a FE400e husaberg and i converted the magura clutch cylinder to a rear brake 6-months ago. the bike behaved fine for months and then just recently it started fading in races-especially if i fell.

i put the plate of a 3rd pad behind the pad on the piston side-this pushed the piston right in. i've checked the fluid level and i'm also using silkolene 5.1 synthetic brake fluid.

in yesterdays race the brake went completely after 3 of the 4 laps.

any suggestions? also is there a better forum in which to put the question here at TT?

no leaks BTW.

regards

Taffy

[gdb11867]

I know that you have already checked this, but it has got air in it. about the only way to bleed them is to force the fluid in from the caliper. try to fill the reservoir as full as you can get it, that way it doesn't get air in it while the bike is on its side. Good luck

[Taffy]

you're right fella, i kept pumping the brake lever wondering what it was? i had a dry squeek at the bars in the lever and then after oilling it i could hear another noise-that bubbly noise!

i tightened a nut and immediately the brake came back!

cheers fella!

regards

Taffy

[Chas_M]

I have discussed this issue with you in the past regarding the utilization of the stock mineral oil Magura clutch cylinder with the LHRB. There is a strong possibility that the problem is related to an incompatibility between brake fluid and the seals in the mineral oil master cylinder, leading to deterioration of the rubber seals. I have been using a brake fluid compatible Magura clutch cylinder for the rear brake in my '04 525EXC for almost two years with no problems at all. I purchased the brake fluid unit through my local Honda shop directly from Magura USA for less than $70.

P.S. I was hopeful (and still hoping) that the stock master cylinder could somehow be successfully set up with the LHRB setup. Note that some of the newer '06 KTM models are now equipped with Brembo brake fluid compatible clutch master cylinders.