As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CUN FLT 816 EN ROUTE CLT TO CUN: FMC FUEL DISAGREE MESSAGE. RIGHT TANK QTY DECREASED AT A HIGHER RATE. AIRCRAFT USED 4000 LBS MORE THAN FLIGHT PLAN. AFTER ARRIVAL CAPT OBSERVED FUEL LEAKING FROM RT ENGINE ON GROUND. MAINTENANCE FOUND LEAK ON RT ENGINE AT FUEL PIPE BETWEEN HP FUEL PUMP TO FFG. FOUND BROKEN O-RING. REPLACED O-RING AND RAN ENGINE WITH NO LEAKS NOTED.