As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAINTENANCE WAS TAXING AIRCRAFT BACK FROM ENGINE RUNS. WHEN THEY PARKED AT HANGER THE #1 BRAKE CAUGHT ON FIRE. FIRE WAS EXTINGUISHED BY MAINTENANCE TECHNICIANS. BRAKE WAS SENT TO OVERHAUL VENDOR TO DETERMINE WHAT THE CAUSE OF THE FIRE WAS. OVERHAUL FACILITY FOUND THE AFT BLEEDER VALVE HAD ERROSION/CORROSION IN THE SEAT AREA THAT ALLOWED BRAKE FLUID TO ESCAPE UPON APPLICATION OF PARKING BRAKE.