What was found
ETOPS - DURING T.O. ROLL HYD Y ENG 2 PUMP LOW PRESSURE INTERMITTENT. Y LEVEL FLUCTUATING DURING TAXI. PERFORMED TSM 29-13-00-810-804-A. OPS TEST OF YELLOW HYDRAULIC SYSTEM FAILED. REMOVED AND REPLACED ENG #2 YELLOW ENGINE DRIVEN PUMP. ENGINE IDLE RUN, LEAK CHECK, AND OPS CHECK GOOD. OK FOR SVC.