What was found
NON-ETOPS FLT 68 HNL-ITO: DURING CLIMB, THE CREW NOTED THAT THE HYDRAULIC A-SYSTEM PRESSURE GAUGE READ 800 PSI. THE CREW RETURNED TO FIELD AND LANDED IN WITHOUT FURTHER INCIDENT. MAINTENANCE PLACED THE HYDRAULIC A-SYSTEM PRESSURE INDICATION ON MEL 29-3-1. AIRCRAFT WAS RETURNED TO SERVICE. DURING OVERNIGHT, MAINTENANCE REPLACED THE HYDRAULIC A-SYSTEM PRESSURE TRANSMITTER IAW AMM 29-31-11. PERFORMED OPERATIONAL AND LEAK CHECK WITH NO DEFECTS NOTED. MAINTENANCE CLEARED MEL 29-3-1. AIRCRAFT WAS RETURNED TO SERVICE.