What was found
(CAN) ON FIRST FLIGHT AFTER REPLACEING THE BRAKE MASTER CYLNDERS WITH OVERHAULED UNITS IN ACCORDANCE WITH AD 2002-08-01. THE RT BRAKE LOCKED UP ON LANDING. THE PILOTS RT BRAKE CYLINDER WAS REPLACED AND THE AIRCRAFT RETURNED TO SERVICE. A SUBSEQUENT TEARDOWN OF THE FAULTY BRAKE MATER CYLINDER REVEALED THAT THE AN380-2-2 COTTER PIN THAT SECURED THE A-50-H-011 STOP WAS BENT PREVENTING THE BRAKE FROM RELEASING.IT IS SUSPECTED THAT THIS PIN WAS BENT DURING TOO AGGRESSIVE PRESSURE BLEEDING OF THE BRAKE SYSTEM.