As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN ACFT PARKED ON UNLEVEL SURFACE FUEL WOULD MIGRATE FROM RT WING TO LT WING. FOD WAS FOUND LODGED IN THE RT WING FUELING TRANSFER CHECK VALVE. REPLACED RT TRANSFER CHECK VALVE ASSY. REMOVED LT TRANSFER CHECK VALVE ASSY, INSPECTED, AND REINSTALLED WITH NO DEFECTS NOTED. REFUELED ACFT AND PERFORMED SATISFACTORY LEAK AND OPS CHECK. FOD SAMPLE APPEARED TO BE FUEL TANK SEALANT MATERIAL.