Please Help!

I'm leaving today for the weekend to go riding in Kennedy Meadows. Unfortunately, my rear caliper was broken a week ago. I got a new one yesterday and got it installed last night. However, after bleeding the rear brake it will not work i.e when the brake is depressed, the back tire continues to rotate. I don't know if I got a bad caliper (factory replacement) or if I'm doing something wrong. Any insight anyone has would be greatly appreciated.


You have air in the system, make sure you are filling the new caliper with fluid, and make sure you are bleeding it correctly. After you bleed it and get a good flow of clean bubble free fluid, tap the caliper firmly to dislodge any traped air bleed it again, let it set over night and bleed it again.

Also try to continue pumping the lever, maybe the pistions are all the way in and you have not cycled the lever thru enough times to get the pistions out.

Fill your caliper before installing makes it easyer. pump it pump it and pump it.

Hopefully its just a stubborn air bubble bleed problem. After checking all the connections, setup a bleed hose and keep pouring brake fluid into the reservoir while pumping thru the system. (I usually do this to force all the old fluid out without loosing the bleed).

I have seen guys get a stubborn air bubble trapped. Once we had to remove the entire brake assembly and bleed while holding it up side down. To my suprise it worked! I was convinced the caliper was bad.

Good luck and have fun at KM!

I did pump the brakes for about an hour. I took the brake lines off as well as the master cylinder. I'm not getting very much flow throught the caliper though when I do bleed the brakes - not much means once I filled the reservoir up I couldn't get the fluid to bleed out through the sytem. I never could get the caliper to take the fluid like it should - it just spits a little bit. There is obvioulsy air in the system, I 'm hoping someone has some tricks to help get the air out.

Thanks again for the help.

take the line off the caliper use a large syrenge or squees bottle to force fluid into the caliper shake it turn it upside down or what ever it takes to get the air out.

Did you try to pour brake fluid into the caliper before you installed it? That may help. You've got an air blockage that is preventing the circuit from being primed. A vacuum bleeder will most likely solve the problem. Any local auto parts store should have one in stock.

using a large suringe from the drug store, do a reverse bleed. i've seen it done on the trails! it makes a bit of a mess on the caliper end but......

anyways fill the suringe with clean brake fluid, and using properly fitting rubber tubing placed on the nipple, force the new fluid up backwards into the system. i've never had to do it that way, but i have seen it done. good luck.

Another way is to use a vacuum pump (either hand operated or electric) to suck the fluid from the caliper. You can get hand pumps at the auto parts for about $35. Works every time.

Or you could just suck on it real hard, don't swallow!! LOL

If it's not attempting to push fluid through at all, the master cylinder seals could have gone. Try sucking it through with a syringe, but if it's been pumped and pumped it could well have done it in.

Back brake?....I'm trying to think of a time when I actually used the back brake. Nope, that right foots always busy doing something else...rarely ever used the back brake. But the reverse fill with a syringe works every guarantees an air free system.

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