What was found
1 HYDRAULIC RESERVOIR: DURING TAKEOFF ROLL. HYD 1 LO QTY CAS CAME ON FOLLOWED BY HYD 1 LO PRESS. TAKEOFF WAS ABORTED. FURTHER INVESTIGATION FOUND HYD 1 RES LEVEL SHOWED 0%. ALSO HYD FLUID IS VISIBLE UNDER LEFT ENGINE. REMOVED AND REPLACED #1 HYDRAULIC SYSTEM PRESSURE HOSE ASSY P/N GD478-1126-1 WITH NEW HOSE ASSY P/N GD478-1126-1. REMOVED AND REPLACED #1 HYDRAULIC SYSTEM RETURN HOSE ASSY P/N AR1048-16 WITH NEW HOSE ASSY P/N AR1048-16. REMOVED AND REPLACED #1 HYDRAULIC SYSTEM CASE DRAIN FILTER P/N AC014F8 WITH CUSTOMER SUPPLIED NEW FILTER P/N ACC314F8. REMOVED AND REPLACED #1 HYDRAULIC SYSTEM PRESSURE FILTER P/N ACC314F12 WITH CUSTOMER SUPPLIED NEW FILTER P/N ACC314F12. SERVICED AND BLED HYDRAULICS. OPS AND LEAK CHECK GOOD. REINSTALLED FWD. LOWER PYLON ACCESS PANEL 412 AB. NO FURTHER DEFECTS NOTED. ALL WORK DONE IAW GL6000 AMM 29-12-21, 29-12-13, 29-10-00, 29-12-25.