As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW OXYGEN LEAK. FOUND CREW OXYGEN SYSTEM CHECK VALVE LEAKING INTERNALLY BACK TO FILL VALVE. REMOVED FILL CAP & FOUND PRESSURE BUILT UP IN LINE. AOG'D ANOTHER CHECK VALVE 642-3246 AOG R5726. RE-CHECKED CREW PSI AFTER REMOVED & REPLACED SAME VALVE FOR INSPECTION. PAX O2 BOTTLE CHECK VALVE REPLACED.