What was found
ON PREFLIGHT WALK AROUND FO NOTICED A FUEL LEAK FROM DRAIN ON ENGINE #1 CAUSING A SIZABLE SPOT ON THE GROUND . DRIPPING AT A RATE OF APPROX 1 DROP/SEC. REMOVED FROM SERVICE. PERFORMED DRAIN MAST INSPECTION IAW AMM 71-71-02-200-801A FOUND FUEL LEAKING FROM #2 DRAIN PORT. OPENED THRUST REVERSER IAW AMMM 78-30-01-910-801A TO INSPECT FOR LEAKS FOUND OPERABILITY BLEED VALVE TO BE LEAKING INTERNALLY AT 2 DROPS EVERY 1-2 MINUTES. CLOSED THRUST REVERSER IAW AMM 78-30-01-910-802A . ALL C/B RESET. REMOVED AND REPLACED #1 OBV REF E175 AMM TASKS 75-32-01-000-801-A/ 400-801-A OPS & LEAK CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.