WHILE HAULING OVERBURDEN FROM A 2800 P & H ELECTRIC SHOVEL, A LIEBHERR 240 TON HAUL TRUCK CAUGHT ON FIRE. IT HAD REACHED THE DUMP SITE AND JUST PRIOR TO HOISTING THE BOX THE OPERATOR SAW FLAME S ERUPT FROM UNDER THE CAB AND FRONT DESK AREA. HE SHUT THE UNIT DOWN, INITIATED THE FIRE SUPPRESSION SYSTEM AND EXITED THE TRUCK. MINE RESCUE UNITS & COUNTY FIRE EQUIP EXTINGUISHED THE FIRE