As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
***WHILE A/C WAS OUT OF SERVICE FOR A HEAVY CHECK*** UPON INSPECTION OF RH WING FUEL TANK, VENT PIPING INSIDE ACC. PNL. 631EB WAS FOUND MISSING ONE O-RING AND CLAM-SHELL SLEEVE. REPLACED IAW AMM 20-10-13-400-801-A. A/C REMAINS OUT OF SERVICE FOR HEAVY CHECK COMPLETION.