My 98 400 has been down for a couple weeks for a broken piston (supprise supprise). Now I went to move it and the brake lever went to the bars and the fluid is running out past the lower cylinder reservoir cap and you can see the cap pulsing when you pull the lever and you also can see the rear brake pads slightly.

any ideas ??

Thanks

 

If I understand you correctly, it sounds exactly like the symptoms of a blown seal in the rear caliper, usually caused by letting the pads wear down too far.

 

same quad, same problem. I just finished repairing the same prob. Like offrder said its the rear caliper seals and or the pads are worn too much. good luck.