Question on brake bleeding

[amehl]

So I just put a new front end on my bike. I put it all together and bled the brakes. Here is a little background.

When I first go my bike, I fixed it up and took it to a very reputable mechanic to give it a "safety check". When I got the bike back, he had bled the brakes and they felt AMAZING. Instant engagement, firm feel, it was incredible.

Now I have bled the the system 3 times, and it still feels like crap. Definitely mushy, with no air coming out of either caliper or master (and when I started, I made sure to push the pistons in).

What am I missing? what is the proper procedure? Do I need to have the brakes off to get it to work like it did when I got it back from the mechanic?

[stryder]

Did you push the pucks back in when you finished?

[amehl]

Originally Posted by stryder

Did you push the pucks back in when you finished?

BAH. you know i didn't do that... that will be the next step. After putting it back together, I guess I was just trying to avoid taking it all apart again. HA!

[470four]

New calipers are a nightmare to burp clean again...

Big syringe with a pipe on it pushing fluid back up through the system usually works, or a vacuum bleeder...

[redpato]

When I replaced my clutch and brake lines it took several attempts to finally get them bled correctly. One suggestion that I got from here was to open the bleeder on the caliper with a bleed hose attached and the end in a small amount of clean brake fluid and let it sit for a couple of hours, kind of letting it self drain. I used a vacuum pump bleeder, I tried pumping fluid up from the calipers to the reservior, the old tried and true method of pumping the lever. It finally just worked after using the vacuum bleeder. Try it several times until it starts building up pressure, it will work.

"in God we trust"

[amehl]

ok I just had another person recommend a vacuum. Maybe that's the way I'll go. I told myself no money spent on my bike this paycheck!

[HumboldtDuc]

you really dont need a vacuum bleeder. Start with bleeding the MC first and once you're sure its been adequately bled, move to the calipers. Bleed one caliper, then then other. Should work just fine. Pump the lever a few times and hold the last pump, crack the bleeder enough to bleed out the aerated fluid, close the bleeder, repeat until desired firmness is acheived.

[mlukason]

I agree with HumboltDuc, you don't need the vacuum bleeder. The system doesn't contain a lot of fluid and the distance from the bleeder to the lever is within easy reach. The old fashion way works fine.

My 2 cents.

[Dmitry]

I agree, vacuum bleeder is a waste of money, probably air trapped in the mater cylinder, "crack" the banjo at the master, watch it bubble. Air tends to gather at the high spots.

MAKE SURE to cover up the bodywork when opening the lines or adding fluid to the reservoir, most brake fluids will melt paint and plastic

[rtzx9r]

Great info, but the mityvac vacuum bleeders are awesome, especially for flushing the fluid out on the bike and cars every year.