KDXRIDER.NET

So there I am at about 13,000' descending a steep, loose rocky slope when my rear brake gives out. Not just a little bit, or you need to pump it to get it back, but completely. Pedal to the stop, no brake at all.

I got to a flat spot and checked it. No leakage, fluid was a little down from the full mark, but not bad. Pads have plenty of life left. The bike is a year old. My buddy on his KX250 thought I was getting sporty coming down. He tried the pedal too, and could see it wasn't getting any resistance, and would move about 3". I figured a seal broke inside, but woulda thought the fluid would come out.

I rode all the way back down working the front, then rode about 4 miles over pretty flat terrain and just before getting back to the house, noticed that rear was working again. WTF? still no fluid leaks. It seems solid now, but I don't trust it. I hate it when something breaks and then heals itself. I know it'll wait until I really need it before it fails again. Ever seen that before? Is the bike jealous now that I am lusting after a KX500, and is trying to kill me? I always thought it must be female.

Overheating...just like your radiators! Common problem on a long decent. Change your fluid to a higher boiling point fluid like Motul and try it again....

Mike, you need to come down from the sky's and get on some nice low level dirt!

Yeah Mike get ya head out of the clouds.

Sounds like a nasty thing to do to its owner. I say put it down and get that KX5 puppy just to show it whos boss.

It sounds like, "Extreme conditions call for extreme fluids." Maybe it just overheated. Was it really squawking before going out?

Geezus, maybe you guys are right. I can just imagine how much power my bike would have at sea level. Maybe I should move back up to Seattle. Hmm .. that would require a divorce though. Can't afford that, I can barely keep up with the coolant payments on my bike. I'll just change the brake fluid till I can find me a KX500 .

Just noticed your signature Vince The guys at work will enjoy that one.

Jason,

No, the brake was fine till that happened. I think maybe it did boil. It looks darker than the stuff in the front now. I'll swap it out. Just need to find some from an SR-71 or something .

Was the front brake overheating too?

nope, but I figure I wasn't using it near as hard as the rear, cuz I'm not that good at stoppies coming down a mountain like that ( or anywhere for that matter). I was going down way faster than I wanted to, and just occassionally using the front with one finger. The steering damper helped a lot in staying on course over the rocks. Too bad I didn't have a helmet cam on.

Had the same thing happen on Johns Peak riding with Carvr onetime

I was riding the back brake, long down hill... all of a sudden lost it ! nuttin!

Later on that day it magically started working, but still was a little squishy feeling

I got home, drained the fluid, noticed it was kinda dirty looking ( kinda like an amber ale) compared to the new stuff I replaced it with (which was more like a Corona).

Never had a problem with it since

I just saw in Motocross Action that Maxima has a new DOT 3 fluid with a boil temp of 550 degrees

Thats higher than damn near any DOT 5 fluid, maybe see if you can find some of it.

I found a place on the net that sells Maximas Dot3 for cheap. http://store.bobscycle.com/browse.cfm/4,36456.htm

Exchange the fluid with likely most any spec'd fluid and it will probably be fine.

I wouldn't worry about using something different...just something new.

..or..what wibby said.

same thing happened to me once, happened to be a very stupid mistake, after getting my bike i went riding and noticed my back brake wasn't working, looked down and the allen pins that hold the brake mount in place were gone. instead of stopping, the whole brake thingy moved up, very convenient, out in the woods and of course with no allen wrench, i didn't feel stupid at all. oh wait, yes i did. , feel free to make fun of me at will
parker

ok, I'll stop off and get some corona then.

Hey parker !!! HAHA !!!

Jus kidding, we all do silly things and are better for it the next time round.

HAHAHAHAHAHAHA!!!! SHUT UP!
just joking, i don't care, if i didn't want to get made fun of i wouldn't have told you.

I put some Maxxima DOT 4 fluid in. I think it's boiling point is a measley 460° though. Anyway when I flushed out the old fluid it had a bazillion little tiny bubbles in it. like the size of pinpoints. That's probably why it don't feel the same after it boils.