Serious Front Brake Problems

[EX4me]

I've already done a search and I'm not finding what I'm looking for. Brand new pads on front of 400ex today. Replaced old fluid also with dot 4. Drained old fluid & then used syringe from bottom bleeder to push up the brake fluid. After this we started bleeding them. Done this a couple of different times. Brake lever never even started tighting up. Broke out my calipers and measured rotors & they are in tolerance with manual. Took off the front wheel & looked while pumping the front break and the piston moves a little but goes right back. It doesn't keep pushing out against the pads while pulling in the lever. No signs of leakage anywhere. Anyone have anymore suggestions on what to do??:confused: :confused:

[protraxrptr17]

You have to bleed the master cylinder first. Take the line off of it and put your finger over the hole. Next just pump it untill it pushes fluid out around your finger. Now put the line back on and pump it up and hold it. Then break the line loose right at the master cylinder. Do this a few times until you think there are no and I mean microscopic bubbles coming out. Then move on to the calipers. Some say start at the farthest one from the master cylinder. I have never been able to tell the difference. Keep going and don't give up. Sometimes it can be a real PIA. You might have to go back and bleed at the master cylinder a few times. Just remember air goes up when its inside a liquid. Thats why it's so important that you bleed it at the master cylinder. Hope I helped.

[EX4me]

Thanks for the help. I'll try this tommorrow. Anyone else got any other suggestions to try why I'm at it. Just got through with all this motor work and other things & now I have no stopping power...lol

[EX4me]

Tried the above & still no brakes. Also had another friend that said to take a wire tie & hold in the front brake lever over night to help bleed off. So far nothing is working & I'm suppose to ride this weekend.:(

[muff]

possibly a blown master cylinder? did it seem like it pushed a lot of fluid when you were trying to bleed just the cylinder itself?

this is just a guess, but maybe when you forced the fluid up the lines it blew something. cause you have play in the system which makes it seem like there are little/no bubbles in the lines, but more of like something is not closing in the master cylinder when you let go of the lever :confused:

[EX4me]

If it will fit, I'm gonna try a Cannondale master cylinder in the morning. If that fixes the problem, I'll know my master needs replacing or rebuilding. Couldn't really tell if it was pushing alot of fluid. I know the piston was pretty easy to push in with hand, when in the past I've used a c-clamp when replacing pads.