As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING PUSHBACK OF ACFT FOR DEPARTURE, THE CREW TRIED TO SET THE PARKING BRAKE. THEY WERE UNSUCCESSFULL AND A LEAK WAS NOTED IN THE MAIN WHEEL WELL AREA. PARKING BRAKE VALVE FAILED AND WAS FOUND IN 3 PIECES. HOUSING ON THE VALVE FAILED INTERNAL PLUNGER TO EXIT VALVE ASSY. HYDRAULIC LINE ALSO DAMAGED DUE TO FAILURE OF COMPONENT AND REQUIRED REPLACEMENT AS WELL.