What was found
ON APPROACH AFTER A 5 HR FLIGHT THE CREW SELECTED GEAR DOWN. THE MAIN GEAR EXTEND, THE NOSE DOORS OPEN BUT THE GEAR REMAIN IN THE NOSE WELL. THE GEAR DISAGREE WARNING ILLUMINATES. CREW EXECUTES A GO-AROUND, THE CREW SELECTS MANUAL GEAR RELEASE. THE NOSE GEAR EXTENDS. LANDING IS UNEVENTFUL. ACFT IS TAXIED TO THE HANGER. THE COMPUTER STORED FAULT INDICATES THE NOSE GEAR SELECTOR VALVE IS TO BE REPLACED. SUBSEQUENT HANGER OPS BEFORE VALVE REPLACEMENT FUNCTIONS NORMALLY. VALVE IS REPLACED AND HANGER CHECKS ARE NORMAL.