As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TRANSIT CHECK, A HYDRAULIC LEAK WAS DETECTED IN THE HYDRAULIC SYSTEM B OF THE ENGINE DRIVEN PUMP. MAINTENANCE PERSONNEL PERFORMED REVISION DETECTING HYDRAULIC LEAK AT HYDRAULIC SYSTEM B IN PLUG OF RETURN FILTER MODULE; SO THE RETURN FILTER MODULE PLUG P/N MS21902-W12 IN SYSTEM B WAS REPLACED IAW AMM 29-11-61, TESTED CORRECT.