What was found
HYD SYS 1 FAIL, E1 HYD PUMP FAIL EICAS MESSAGES AND HYD 1 QTY 0 IN CRUISE. REMOVED AND REPLACED #1 ENGINE DRIVE HYDRAULIC PUMP. FOUND AFT DPI TO NOT BE SEATED ON MANIFOLD DUE TO BACKUP RING INSTALLED INCORRECTLY REMOVED AND REPLACED AFT DPI WITH NEW ORINGS AND BACKUP RING VERIFIED OTHER TWO DPIS WERE INSTALLED CORRECTLY. SERVICED #1 HYD SYSTEM TO FULL. COMPLETED DPI INSTALL. LEAK/OPS CHECK SAT. COMPLETED #1 EDHP INSTALL. OPS/LEAK CHECK SAT. REMOVED AND REPLACED #1 HYD PUMP FILTERS. NO CONTAMINATION NOTED. OPS AND LEAK CHECK SAT.