As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BRAKES LOCK UP AFTER PARK BRAKE IS RELEASED. SECOND OCCURRENCE OF THIS PROBLEM. FIRST OCCURENCE, BRAKE CONTROL VALVE REPLACED PER ACFT MFG. SECOND OCCURRENCE, FOUND INTERNAL SEAL BROKEN ON RT OTBD BRAKE SHUTTLE VALVE AND FOUND RT MODULATOR VALVE CONTAMINATED WITH SMALL PIECES OF O-RING. REPLACED MODULATOR VALVE.