As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING SCHEDULED MAINTENANCE, IT WAS DISCOVERED THAT THE PARKING BRAKE WAS LOSING PRESSURE. MAINTENANCE DETERMINED THE PARK BRAKE VALVE WAS LEAKING INTERNALLY AND REPLACED IT. THE NR 2 SYSTEM PX CHECK VALVE ON THE PARK BRAKE MANIFOLD WAS ALSO REPLACED.