EE WAS TAKING A LOAD OF ABC TO THE THE PIT FLOORWITH A CAT 980C LOADER WHEN THE BRAKES FAILED. EE JUMPED OUT AND LANDED ON HIS LEFT LEG BREAKING THE BONE(FEMUR). THE LOADER ROLLED ABOUT 40 F EET AND STOPPED AT A BERM. THE BUCKET WAS NOT LOWERED AND THE PARK/EMERGENCY BRAKE WAS NOT ACTIVATED.