As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE BEING TAXIED FOR TAKEOFF, THE RT BRAKE FAILED, RESULTING IN THE ACFT PROPELLER TO CONTACT A TAXIWAY LIGHT RESULTING IN IRREPAIRABLE DAMAGE TO THE PROPELLER. UPON VISUAL INSPECTION OF THE RT BRAKE MASTER CYLINDER THE COVER CHAMPHER WAS DAMAGED NOT ALLOWING THE PISTON ROD END TO FULLY SEAL WHEN THE TOE BRAKE WAS PRESSED RESULTING IN A DECREASE IN HYDRAULIC PRESSURE AND LOSS OF DIRECTIONAL CONTROL.