What was found
POSSIBLE FUEL LEAK IN #1 ENG AT HMU DRAIN REF L/P 60096874. GROUNDED - YES. PERFORMED ENG VENTS & DRAINS INSPECTION. DRAINS & VENTS NO LEAKS NOTED PER B737-900 AMM 71-71-00-200-801-F00. INSPECTED #1 ENG HMU FOR LEAKS WITH ENGINE RUN. NO LEAK NOTED FROM HMU. FOUND FUEL LEAK AT FUEL HEAT SERVO VALVE. STEADY STREAM OF FUEL LEAKING DURING ENG RUN. TRIED TO SECURE BOLTS AT GASKET. NO HELP. R/R #1 ENGINE FUEL HEATER SERVO IAW AMM 73-11-07. PERFORMED ENG RUN IAW AMM 71-00-00-700-821-F00, OPS CHECK GOOD. NO LEAKS NOTED. OK FOR SVC.