What was found
PERFORMED HIGH SPEED TAXI AFTER BRAKE MAINTENANCE, TAXIED BACK USING NORMAL BRAKING PROCEDURE. UPON RETURN TO RAMP, LEFT WHEEL/BRAKE ASSEMBLY WAS ON FIRE, RIGHT WHEEL/BRAKE ASSEMBLY SMOKING. EXTINGUISHED FIRE WITH PURPLE K, DRY CHEMICAL (B-C) EXTINGUISHER. INSPECTED LEFT AND RIGHT MAIN GEAR, NO OTHER DAMAGE NOTED. REMOVED AND REPLACED BOTH LT AND RT MAIN GEAR WHEELS AND BRAKES, BOTH BRAKES HAD BEEN SENT TO OVERHAUL SHOP TO DETERMINE CAUSE OF SMOKE/FIRE.