seeking front brake insight

[Bluebandit103]

I have a 2002 yz250 and have been over my front brake time and time again trying to fix them. My front brake grabs and has pressure but then slowly loses pressure and stops grabbing. I have back bled them, I have tried vibrating any air out of the line, I have bled and bled but they still lose pressure. There are no visible leaks and I have checked the caliper and it seems to be functioning fine. If any one can give me any advise I would greatly appreciate it. Thanks

[Hkraack437]

How's your brake fluid?

[RCannon]

I imagine his fluid is god since he's bled them so many times.

I would replace or rebuild your master cylinder. It sounds as if its the part not holding pressure.

[Bluebandit103]

Ya that's what I was thinking,I just wanted to check on here first I always get great advise.

[tidtid]

Master cylinder needs rebuilding. The orings in it is bad, once you rebuild it it should pump up in just a few pumps.

[Bluebandit103]

Thanks ordering one now.

[shagger]

Ebay a Honda master and caliper. It'll bolt right on, though you may have to swap the backing plates. It's an instant brake upgrade.

[Bluebandit103]

Thanks for all the help, rebuilt the master cylinder and it works great.