As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THIS AIRCRAFT IS EQUIPPED WITH OPTIONAL INBOARD FUEL FILLER CAPS. THE FUEL FILLER CAP ADAPTER ASSY. (P/N C156005-0105) HAS A SPRING LOADED FLAPPER WHICH IS DEPRESSED BY THE FUEL DISPENSING NOZZLE WHILE FILLING THE TANK. THE FLAPPER HAS BEEN HITTING ON THE (P/N 2600101-48) VENT LINE ASSY INSIDE THE TANK BAY AND HAS WORN THE VENT LINE APPROXIMATELY HALF WAY THROUGH ITS DIAMETER. DEFECT WAS DISCOVERED BECAUSE FUEL FILLER ADAPTER WAS REMOVED FOR MAINTENANCE.