No pressure in front brake

[crazycracker]

Hi, i have a 2008 yz250 and just put on steel braided brake lines. The front brake refuses to build pressure??? i try to bleed it but it doesnt seem like i am doing much. Any help would be appriciated.

[FPMXer]

You have to get all the air out of the system or it will not hold pressure. Brakes can be a major pain in the ass. I have a vaccum brake bleeder and it works wonders.

[slagburn666]

I use a vacuum pump as well. except for the real pain ones, I have a suction gun that I fill with clean brake fluid. I put it on the bleeder and push brake fluid through to the master. With the master cap off. That will usually push the air out. (air rises)

[mtdirtbag]

Go down to the local Agri business store and purchase a large syringe, generally indicated as a bovine syringe. The cost is a few dollars, and as mentioned before use clear tubing to go from the syringe to the bleeder valve and push the fluid to the master. It's best to have someone help you by catching the fluid pumped out the top of the master, brake fluid can be corrosive to some materials.

[WAMXP1MP]

Save you money and instead of just relying on the pump n bleed method at the master cylinder. Push up the brake and them push the calipar apart with a screw driver and the air bubbles will bleed out of the master cylinder faster since air want's to travel up. I had to deal with this when I but braided lines on my bike and found this speed's up the bleeding process alot.

[crazycracker]

i bought one of the vacume bleeders, i am getting alot of bubbles in the resover for the vacume bleeder but not much oil??

[OW38B]

A brake system should have no air bubbles in it. Sometimes flicking the brake hose will free up trapped air in the hose.

[RCannon]

The vacuum things are a PITA because the bleeder never seals properly when its cracked open. You just abotu have to cover the threads in Teflon tape to get a good vacuum.

Its hundreds of times easier to push the pistons in...either with the caliper loose or fixed to the fork.

[Coadster68]

I had the same problem with my back brake. I pushed the piston out with air via the bleeder, and then filled the cavity where the piston goes with brake fluid. Make the the MC cap is off, and put the piston back in (after closing the bleeder) and bottom the piston out. That will push enough fluid in and enough air out to be able to restore pressure and then just bleed it normally.

[crazycracker]

Got it to work, tricky little mechanism

[Coadster68]

It certainly is if you havent tackled it before. I was up until 4:30 in the morning before I ginally found out how/what to do. ?