What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS AIR RETURNED TO PHL ON ACCOUNT OF GREEN HYDRAULIC SYSTEM LOSS (SYSTEM OVERHEAT). EMERGENCY DECLARED AND THE AIRCRAFT WAS OVERWEIGHT FOR LANDING. MAINTENANCE PERFORMED T/S IAW TSM 29-11-00-810-802-A UNABLE TO REPRODUCE GREEN HYD. RESERVOIR OVERHEAT. POST FLIGHT REPORT SHOWED GREEN HYD. PRESS SW 2. REMOVED AND REPLACED G HYD PRESS SW 10CE2 IAW AMM 27-97-17-000-001/400-801 OPS CHECKS/LEAK CHECKS GOOD OK FOR SERVICE.