As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE EN-ROUTE, THE CREW NOTED THAT THE B-SYSTEM HYD QUANTITY WAS DECREASING AND THE LOW LIGHT ILLUMINATED. ACFT DECLARED AN EMERGENCY AND LANDED WITHOUT INCIDENT. POST FLIGHT INSPECTION WAS PERFORMED, NOTING THAT THE UPPER RUDDER LOAD LIMIT RELIEF VALUE WAS LEAKING. R & R RUDDER LOAD LIMITING VALUE AND PERFORMED OPS CHECKS WITH NO DEFECTS. ACFT WAS RETURNED TO SERVICE.