110cc. I have no rear brakes. The reservoir has fluid. I tried bleeding the brakes but get nothing when I unscrew the bleeder valve, not even fluid. I completely disconnected the line at the brake caliper and have no fluid coming out even when I pump the brakes. Is this a air issue or a master cylinder failure? The ATV has seen very little use and has sit for about two years.

Any help would be appreciated!

 

Could be either. In my experience the only way to bleed Quad brakes is to clamp a set of vice grips on the flexible line below the master cylinder so that the pipe blocks. This won't work on those braded pipes, only rubber ones. Open the bleed screw, remove the grips and press the lever down, re-fit the grips and release the lever, repeat, check the reservoir is full, and keep going until the brakes are bled. If you don't get a locked lever when you try pushing it with the clamp in place, after the first couple of "pumps" you have a faulty master cylinder.

 

Thank you for the reply. I will give this a try today. Seems like if the rear master was bad it would leak around the plunger rod....just my thoughts.....hoping this is an air bleeding thing.

 

Could also be a clogged line since it sat. The quad I have sat for 5-6 yrs before I worked on it. And I had to physically clear out the lines with wire and then flush the rust out with brake cleaner. Hopefully yours aren't that bad but its a possibility