What was found
AIRCRAFT RETURNED OF FLIGHT DUE TO DURING CLIMB AT 26,000 FEET, THE CREW OXYGEN LOW LIGHT TURNED ON. MX PERSONNEL PERFORMED AN OXYGEN CREW INSPECTION IAW MM 35-12-85, DETECTING OXYGEN BOTTLE MANOMETER WAS INDICATED 310 PSI. THE OXYGEN BOTTLE WAS REPLACED IAW AMM DMC-B787-A-12-15-08-00B-200A-A, TESTED CORRECT.