As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING ROUTINE INSPECTION,THE NR 1 BRAKE WAS FOUND TO BE LEAKING. TEAR DOWN OF THE BRAKE UNIT REVEALED DETERIORATED O-RINGS ON TWO OF THE BRAKE PISTONS, AND THE BACK-UP RINGS WERE FOLDED OVER THE PISTON, BETWEEN THE PISTON ASSY AND THE SLEEVE. THE BRAKE UNIT WAS REPLACED AND THE AIRCRAFT WAS RETURNED TO SERVICE.