What was found
CREW REPORTED- ON INITIAL CLIMB AFTER TO FROM CSL, HYD1 QTY LOW EICAS APPEARED. HYD1 QTY INDICATED TOP OF AMBER BAND. WITHIN APPROXIMATELY ONE HOUR, HYD1 QTY DECREASED TO 0 AND PRESSURE BEGAN FLUCTUATING. SHORTLY AFTERWARDS HYD1 SYS FAIL EICAS APPEARED. FOLLOWED QRH AND LANDED LAX. MX ACTION- MX TECH FOUND L/H ENGINE DRIVEN PUMP HYDRAULIC PRESSURE HOSE CHAFED AND LEAKING ALONG MID LENGTH. REPLACED LEAKING HOSE ASSY AND SYS #1 ENG DRIVEN PUMP. PUMP ASSY PN: OFF/ON 971808 / 971808 SN: OFF/ON MX646929 / MX636936 HOSE ASSY PN: OFF /ON AE713790-16, NSN.