As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOGPAGE 7907967 FLT 1045 DTW CLT AIR TURN BACK GREEN HYDRAULIC LOW LEVEL AND OVERHEAT. TOTAL LOSS OF GREEN SYSTEM WAS EXPERIENCED DURING CRUISE. THE FLIGHT DECLARED AN EMERGENCY AND RETURNED TO CLT. R&R NR 1 ENGINE HYDRAULIC PUMP. FLUSHED LINES AND REPLACED FILTERS. OPS AND LEAK CHECK WERE GOOD.