As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUEL BEGAN VENTING FROM THE RIGHT WING AFTER TAKEOFF. THE LEFT FUEL QUANTITY DROPPED 800 LBS BELOW RIGHT SIDE. BOTH FUEL QUANTITIES WERE BELOW 8,800 LBS. FLIGHT RETURNED TO YUL AND LANDED WITHOUT INCIDENT. MAINTENANCE RESET CLIMB VENT VALVES.