2005 Kawasaki KAF400 Mule 600 and Mule 610 4x4 Service Manual, Page 44Get this manual
PERIODIC MAINTENANCE 2-25 Periodic Maintenance Procedures
the upper Fill the reservoir to (MAX) level line [A]Upper Level Line
Lower Level Line (MIN) [B] Apply the brake forcefully for few seconds and check for fluid leakage around the fittings
WARNING
If the brake pedal has soft or "spongy feeling" when it is applied, there might be air in the brake lines or the brake may be defectiveSince it is dangerous to operate the vehicle under such conditions, have the brake system serviced immediately
Brake Fluid Change
Tilt up the front cargo hood Remove: Cap Rubber
Brake Fluid Reservoir Cap Level the brake fluid reservoir [A]