As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) APPROXIMATELY 2HRS INTO FLIGHT CREW CONTACTED MOC THROUGH DISPATCH TO DISCUSS MIGRATION OF HYD FLUID FROM RT SIDE TO CENTER. AFTER DISCUSSION IT WAS DECIDED NOT TO CROSS THE OCEAN & DIVERT BACK FOR MX TO INVESTIGATE FURTHER. RESOLUTION FOUND SCHRADER VLV ON C HYD SYS LEAKING. REPLACED THE SCHRADER VLV. CARRIED OUT FIM 29-11-00-810-830 BLOCK 1, 2, 3 & 5 NO FAULT FOUND. OPERATE THE LG HANDLE IN UP & OFF POSITION FOR 1 HR NO TRANSFER OF HYD FOUND.