As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT HYDRAULIC SYSTEM QUANTITY AND PRESSURE DROPPED TO ZERO AFTER TAKEOFF. CREW DECLARED A YELLOW EMERGENCY AND FLIGHT WAS RETURNED TO YYZ. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND RIGHT LOWER BRAKE FUSE LEAKING. REPLACED BRAKE FUSE. LEAK AND OPERATIONAL CHECK NORMAL. AIRCRAFT RETURNED TO SERVICE.