As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OXYGEN SYSTEM LEAKING: FOUND OXYGEN SYSTEM NON-RETURN VALVE INOP AND ALLOWING OXYGEN TO FLOW BACKWARDS AND LEAKING OUT OF FILLER PORT. REMOVED AND REPLACED NON-RETUEN VALVE AND LEAK CHECKED GOOD. THIS NON RETURN VALVE WAS JUST INSTALLED 9 MONTHS AGO FOR THE SAME ISSUE.