As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED A STRONG HYD FLUID ODOR COMING FROM THE NR 2 PACK. AFTER ARRIVING AT THE GATE AND SHUTTING DOWN THE ENGINES. AIRCRAFT GROUNDED. MAINTENANCE DETERMINED THE SOURCE OF THE ODOR TO BE THE YELLOW ELECTRIC HYDRAULIC PUMP. REPLACED YELLOW SYSTEM ELECTRICAL PUMP IAW AMM 29-24-51-000-001 AND 29-24-51-400-001-A.