As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RTFL UNDER AMBER ALERT DUE TO LOSS OF GREEN HYDRAULIC SYSTEM. A/C WAS TOWED TO GATE. FLUID LOSS DUE TO FAULTY RH MLG DOOR BYPASS VALVE. REPLACED THE DOOR BYPASS VALVE AND NR 1 ENGINE DRIVEN HYDRAULIC PUMP AS A PRECAUTIONARY MEASURE. CHECKED HYDRAULIC SYSTEM FILTERS AND DID NOT FIND ANY METAL FRAGMENTS.