bleeding my front brakes..

I have been trying to bleed the front brakes on my 05 450f. I have all the air out of the lines, at least I think I do. But the brakes still seem really spongy. I can pull the lever to my handlebars. Is there any certain way to bleed them so it will pump up the way it is supposed to? I have just been pumping the lever, holding in and loosening the bleeder screw, then tightening the screw back up and releasing the lever. I have done it quite a few times but still no progress.

Anybody can bleed brakes.....not many do it right!We use a few different ways,1st is to go from the bottom and push the fluid up with a big syringe.

Another way is to pull the whole brake system off the bike and put it so the caliber is on the top and the master on the bottom and do it the same way you are doing it now.It works better because you are now pushing air up instead of down!Another way is to use a piece of tubing and a small jar,put some fluid in the jar and with the tubing over the bleeder and in the jar pump away.

I have the same problem on my 02 YZ 250F.

Dont forget to tie wrap your lever to your bar overnight just to let any bubbles out. It will help too.

It's funny this post came up today, My brakes were getting a little spongy, and the pads were worn anyway. So I installed new brake pads (front on a 2004 Yz450f) and used a typical automotive store bleed kit that you pump the fluid into a canister. When all was done, the brakes definately had way less sponge, but there is still a little there. I really bled the snot outta them so what else should I try?? I will try the recommended post above about keeping the brake actuated overnight, but if that doesn't cut the mustard, what's next to try???



I'm just going to try all the ways mentioned. Hopefully I can get somewhere with these dang things. Thanks guys.

Two things to try:

Tickle bleeding. Pull the lever only through the first little bit of travel so that the air that is caught up in the top of the master cylinder is pushed up through the feed port and into the reservoir.

Gravity bleeding. Fill the MC to the rim and leave it open. Have your brake fluid ready. Put a pan under the caliper, and open the bleeder. Now, just let the fluid drain through, keeping the reservoir filled as the level falls. When you see clear fluid with no bubbles for at least 30 seconds (more is good), close it off, tickle a couple times, and the lever should feel better.

I assume you are gravity bleeding the brakes. Make sure you have a clear hose routed up and over the wheel and then into a catch can. Top off the MC reservior, pump the lever about 4 times, hold, open the bleeder and keep the lever at the bar. Close the bleeder, release the lever. Repeat until there is no more air.

now sometimes you need to open the bleeder then pump the lever from about 1/4-3/4 of the stroke rapidly. If you do this, you will push out the remaining air in the caliper and you will have a firm lever again.

No hose is required in the method I described. It works quite well once you break any air bubble blockage that exists at the feed port.

Good news guys, After Zip-Tying the brake lever to the throttle (holding the brake on throughout the night) there is virtually no more "sponginess". I felt a tiny, tiny amount of "sponginess" when the brake is almost fully applied, but I think I can live with that. Maybe I'll try the Zip-Ty method overnight again, and see if it gets rid of the remaining little bit.

Thanks again for the help everyone.


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