What was found
(CAN) ON DEPARTURE LT HYD PRESSURE LIGHT ILLUMINATED IN FLIGHT WITH HYD PRESS. READING ZERO. AIRCRAFT LANDED. MAINTENANCE FOUND LT EDP INOPERATIVE. LT EDP SWAPPED WITH RT EDP AND AIRCRAFT DISPATCHED IAW MEL 29-5.EDP P/N AS666411-L-5666 S/N MX134145-4M. THE LT HYDRAULIC QTY LOW LIGHT ILLUMINATED IN FLIGHT WITH QTY INDICATION OF 3 QTS WITH SYSTEM PRESSURIZED. FOLLOWING INVESTIGATION BY MAINTENANCE, FOUND LT PIPE ASSY-FUSELAGE SECTION HYD SYSTEM PRESSURE P/N 7936907-615 CRACKED AT FLARE.