What was found
PILOT REPORTED THAT AFTER LANDING AND EXITING THE RUNWAY, HE ATTEMPTED TO MAKE A LEFT TURN ON A TAXIWAY USING DIFFERENTIAL BRAKING. HE STATED HE HEARD A POPPING SOUND AND LOST EFFECTIVE BRAKING OF THE LEFT BRAKE. WE BROUGHT PLANE IN FOR MAINTENANCE TO CORRECT THE ISSUE. THE INSPECTION REVEALED THAT THE LEFT BRAKE ROTOR WAS COMPLETELY SHEARED AT THE RADIUS CLOSEST TO THE INNER WHEEL HALF. NO LEAKS IN THE BRAKE SYSTEM WERE DETECTED. INSPECTED THE WHEEL AND SURROUNDING AREA FOR DAMAGE WITH NONE NOTED. THE LEFT BRAKE ROTOR WAS REPLACED WITH NEW, AND THE AIRCRAFT WAS RETURNED TO SERVICE.