As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAIN EXECUTED GO AROUND DUE TO UNSAFE GEAR INDICATION / ALT GEAR EXTENSION USED. AIRCRAFT LANDED SAFELY IN EWR AND MX CALLED TO AIRCRAFT. T/S TO SELECTOR VALVE P/N 48300-3. REMOVED AND CLEANED EXCESS SEALANT FROM THE END OF THE PISTON ON THE SELECTOR VALVE.