As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
5392-EWR-AFTER TAKEOFF LANDING GEAR WOULD NOT RETRACT, AIRCRAFT RETURNED FROM FLIGHT AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED AND FOUND HYDRAULIC BY PASS PIN POPPED, MAINTENANCE REPLACED HYDRAULIC RETURN FILTER, RESET BY PASS PIN AND PERFORMED GEAR SWING, SYSTEM OPERATIONALLY CHECKED GOOD.