Hot Brakes

[ruger]

So I was coming off this trail this morning, fairly steep downhill for several miles. Got towards the bottom and the back brake went completely gone, absolutely nothing.

I checked it out and everything looked fine, but the rear cylinder wouldn't build any pressure.

I made it down & went home. When I unloaded the bike, the rear brake was back to normal. I've got the brakes hot before, but never had one go completely out all of the sudden.

Is this normal?

 

[Zerotact]

Flush the brakes out and put new,clean, high quality brake fluid in it.

 

[dirt bike dave]

It's normal with low quality or old brake fluid.

When the fluid boils, you can't activate the brake because your are just compressing the bubbles cuased by the boiling. When the fluid cools, the brake will work again.

Try Motul 600 - it has a much higher boiling temp. Brake fluid absorbs water from the air, which lowers the boiling point over time. Replacing the fluid annually is a good idea.

 

[ruger]

I'll give that a shot. It got a little sporty coming down off that mountain without a back brake!

Thanks,

 

[vitolayne]

Me too

Losing the rear brake has happened to me more than once. When it cools down, it works normally. After a rat race through the woods, I can be seen in a creek kicking water onto my rear disc and caliper before I take back off again. Motol has been recommended to me and it should work better with it's higher boiling point. I think that I just ride my brakes too much. Changing the fluid more often would help too, if I wasn't known as the "lack of maintence king" around here! We're going to Colorado around Labor Day, so I definitely need stopping power down those hills (mountains). Vito