As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CENTRE SYSTEM HYDRAULIC QUANTITY MESSAGE ON EICAS ON TOP OF DESCENT. QUANTITY CONTINUED TO DROP SLOWLY DURING DESCENT AND FLAP/GEAR EXTENSION FOUND TO BE A LEAK FROM THE INBOARD RT ELEVATOR POWER CONTROL ACTUATOR (PCA). REPLACED ACTUATOR.