What was found
LIH FLT 146 EN ROUTE PHX TO LIH. ON FINAL APPROACH, AFTER SELECTING FLAPS 25, THE CREW RECEIVED AN EICAS MESSAGE OF T/E FLAP DISAGREE. THE CREW PERFORMED A GO-AROUND AND COMPLETED THE APPROPRIATE QRH PROCEDURES. ON NEW APPROACH, THE CREW SELECTED FLAPS 20 AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE PERFORMED AN OPERATIONAL TEST OF THE FLAP/SLAT ALTERNATE DRIVE SYSTEM, TRAILING EDGE FLAP LOAD RELIEF SYSTEM, AND THE TRAILING EDGE SYSTEM. MAINTENANCE FOUND THE RIGHT INBOARD FLAP TRANSMISSION OIL QUANTITY LOW. MAINTENANCE SERVICED THE RIGHT INBOARD FLAP TRANSMISSION TO FULL. THE FLAP SYSTEM TESTED NORMAL AFTERWARDS.