Brembo Rear Brakes

So I am riding yesterday and I noticed that during long down hills my rear brake was going away. I thought at first that I boiled them and that was the problem, but upon further inspection and analysis I found that while holding steady pressure on the peddle it would slowly continue to depress until bottomed out. At this point the brake pressure was gone and the bike would roll freely. Fluid level is correct and fresh. No observed fluid from the master cylinder, brake caliper, or line.

Any thoughts or experiences?

simplest thing id imagine is some how you have a lot of air in the line?

I had the same problem with my 08 TC250.....there was a small slice in the rear caliper piston seal....the fluid runs out the bottom of the caliper and off the swingarm:jawdrop:....if you find this is the case..a KTM dealer will have the brembo kit.....my husky dealer didnt

Mine didnt lose a lot of fluid....just a few drops...and was pulling air back in....

If you can not find any external evidence of a leak ( which I doubt you have as the fluid level is OK and does not seem to be going down ) then the Master cyl is bypassing internally, new o-rings should cure your dilema.

First from the initial sound of things.... I'd still try and re-bleed the brakeline one more time, because it still sounds like there's air in the brakeline.

But if that doesn't work.... then it sounds like it's time for a master cylinder rebuild kit!

Looks like a master cylinder rebuild. I bleed the brakes again on the off chance it was air, but I still have the gradual bleed down to bottoming out.
I will post the out come after I get the kit and rebuid it.

I have had problems with the rear master cylinder seals since 04 on my ktm's now on my 08 husky. I must admit that i am a serious brake drager think i use the brake pedal as a foot peg. I race ecea enduros [tight trails] i remove master cylinder piston assembly and rotate seal position 90 degrees after two races. The top seal is always damaged at the drilled oil passage area. KTM sells the piston seals seperate part #54813064200 for $3.99 husky didn't sell either the seals or the master cylinder piston kit.

Thanks for all of the replies guys. It turned out to be a damaged top seal as suggested. Replaced it tonight and all it well now.
I did end up damaging the dust boot though, but that's an easy fix. I did McGiver a temp boot until I can get back up to a shop.