As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, RETRACTED FLAPS AND RECEIVED AN A-HYDRAULIC LOW PRESSURE INDICATION AT FLIGHT ENGINEER PANEL AND PILOTS FWD PANEL. FOLLOWED HYDRAULIC LOSS PROCEDURES. AIRCRAFT RETURNED TO DEPARTURE AIRPORT WITHOUT INCIDENT. REMOVED AND REPLACED (A) SYSTEM HYDRAULIC MOD PACK. OPERATIONAL CHECK NORMAL.