What was found
DURING CLIMB, CREW RECEIVED WING FUEL IMBALANCE MESSAGE, AND REPORTED RIGHT WING FUEL LEAK INFLIGHT. CHECK LIST FOLLOWED, EMERGENCY DECLARED, AND UNSCHEDULED LANDING AT ALTERNATE AIRPORT PERFORMED WITHOUT INCIDENT. MAINTENANCE EVALUATION FOUND EVIDENCE OF FUEL EXITING RIGHT WING VENT VALVE CAUSED BY DEFECTIVE DEFUEL VALVE. DEFUEL VALVE WAS REMOVED AND REPLACED IAW AMM.