I have an 04 650 and from time to time the front brake will not work. When i squeez the lever it will go all the way to bar, has no pressure. So i will pump brake and eventually pressure comes back. Also i noticed that from the reservior when i squeez lever air bubbles coming out from it. Do i need to just bleed brakes?? I have not seen any signs of brake fluid leaking anywhere.

 

The last time I saw this problem the fluid level was just low enough that during the traversing of rough ground air got into the piston portion of the master cylinder. Filled to the full (top) level line and the problem dis appeared. The level was not down to the low level line either.

 

this is what i was experimenting with mine and i had asked about it last week on here (headline: brakes never work). ive had mine fixed 6 times. still does not work and a guy i ride with has the H1 and his did the same this past weekend. bear4570 and discussed this last week and decided to get a whole new assembly. i keep getting mine fixed under warrenty but im tired of taking it in every weekend. let me know what you do and if it fixes it. good luck!