What was found
FUEL AUTO TRANSFER FAULT ECAM IN CLIMB. SELECTED MAN AS PER ECAM. REALIZED NR 1 TANK WAS FEEDING BOTH ENG AND UNBALANCE INCREASED. UNABLE TO GET FUEL FROM CENTER OR RIGHT TANK. RETURNED TO YYZ. RECTIFICATION: TSM TASK 28-12-00-810-801 CARRIED OUT. OVERPRESSURE PROTECTOR DISK 96QM RUPTURED. REMOVED TASK 28-12-41-000-003 AND INSTALLED TASK 28-12-41-400-003 MM TASK 28-25-00-869-001 FUEL TRANSFER AND PANEL LEAK CHECK CARRIED OUT SERVICEABLE.