HAULER OPERATOR WAS MAKING HIS FIRST LOAD OF THESHIFT TO THE LOADING STATION FROM DIII PIT ON #32026 HAULER. HE WAS APPROX.2 MILES FRO THE PITON #7 RAMP HAUL ROAD WHEN HE NOTICED FLAMES AROU ND THE HITCH AREA OF THE HAULER. HE STOPPED THE MACHINE SET HIS PARKING BRAKE AND ATTEMPTED UNSUCCESFULLY TO EXTINGUISH THE FIRE WITH A 20LB EXTINGUISHER. WATER TRUCKS CALLED FIRE PUT OUT 8:45