As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAX - CREW REPORTED UNWANTED FUEL TRANSFER FROM CENTER TANK TO RIGHT TANK. FLIGHT RETURNED LAX LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED RIGHT MAIN TANK FORWARD AND AFT BOOST PUMP DISCHARGE CHECK VALVES. SYSTEM GROUND CHECK NORMAL OPERATION.