As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING CRUISE AFTER DEPARTURE THE ACFT ENCOUNTERED A YELLOW HYDRAULIC FAILURE. IN CONSULTATION WITH MAINTENANCE AND FLIGHT DISPATCH, THE FLIGHT CREW DIVERTED BACK TO DEPARTURE AIRPORT. RESOLUTION ENGINE 2 YELLOW HYD PRESSURE LINE REPLACED IAW AMM 29-13-49-400-008-A. ENG NR 2 FIRE BOTTLES REINSTALLED IAW AMM 26-21-41. AFT MOVEABLE FAITING, AFT LOWER FAIRING AND AFT FIXED FAIRING REINSTALLED IAW AMM 54-54-00-400-001-A.