As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DECLARED AN EMERGENCY INTO ATL VIA ACARS DUE TO THE LEFT HYDRAULIC QUANTITY DROPPING DOWN TO .42 ON FINAL APPROACH. HYDRAULIC PRESSURE REMAINED GOOD. THE AIRCRAFT LANDED SAFELY. MAINTENANCE REPLACED THE LEFT MAIN GEAR ACTUATOR PER B757 AMM 32-32, BECAUSE THE ACTUATOR O-RINGS "BLEW OUT". NEW STRUT WAS SERVICED AND LEAK CHECKED AND THE AIRCRAFT RETURNED TO SERVICE.