THE HYDRAULIC PUMP WHICH OPERATES THE BRAKE ON THE HOIST BURNED UP & QUIT PUMPING FLUID. THIS CAUSED THE BRAKES TO SET. THE HOIST WAS HOOKED TO THE JUMBO-DRILL & IT WAS POSITIONED AT THE SWITC H ON THE SURFACE. NO DAMAGE OR INJURY OCCURRED. THE HYDRAULIC PUMP & TANK WERE CHANGED OUT W/SPARE & OPERATION OF THE HOIST RESUMED. MSHA INSPECTOR MADE INSPECTION OF THE HOIST ON 3/19/02.