As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ADVISORY MESSAGE FOR LOW CREW OXYGEN DURING CRUISE AT FL340, 550 PSI. FOLLOWED TSM 35-10-00-810-827 AND PERFORMED LEAK CHECK OF CREW OXYGEN CYLINDER AND FITTINGS, NO LEAKS NOTED. PERFORMED OPS TEST OF FLT CREW QUICK DONNING MASK IAW AMM 35-12-41-710-001. FOUND CAPTAIN`S OXYGEN MASK LEAKING. REMOVED AND REPLACED THE CAPTAIN`S OXTGEN MASK IAW AMM 35-12-41 PB 401. PERFORMED OPS TEST IAW AMM 35-12-41-710-001 OPS TESTED NORMAL, NO LEAKS.