What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT DIVERTED TO MIA DUE TO THE FLIGHT CREW REPORTING THAT INFLIGHT HAD YELLOW HYDRAULIC RESERVOIR GO TO ZERO. COMPLIED WITH ECAM. THE AIRCRAFT LANDED SAFELY AT MIA WHERE IT TOWED TO THE GATE. MAINTENANCE ISOLATED THE SOURCE OF THE LEAK TO THE PTU AND PRESSURE LINE FRANGIBLE FITTING, MAINTENANCE REPLACED THE PTU (AALA202604084859) AND THE PRESSURE LINE (AALA202604082721). A SATISFACTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO ISSUES NOTED.