As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FUEL PUMP 646212-1 USUALLY USED ON TCM ENGINES IO520. THIS FUEL PUMP IS ONE OF SEVERAL FUEL PUMPS FOUND TO LEAK PAST THE SEAL PN 646181. ALSO, NEW PRODUCTION OF THIS SEAL IS FOUND TO BE SMALLER THAN THE OLDER VERSION WHICH CAUSED IT NOT TO BE SEATED FIRMLY IN THE BODY.