What was found
#1 ENG FUEL HEATER IS LEAKING FUEL. GROUNDED - YES. REMOVED DRAIN PLUG & DRAINED FUEL FROM #1 ENG FUEL FILTER COVER. INSTALLED NEW O-RING & INSTALLED DRAIN PLUG & SAFETIED PER B737-900 AMM 73-11-07. WHILE INSTALLING FUEL HEATER SERVO, IB CTR STUD WAS PULLING OUT WHILE TORQUING NUT. REMOVED FUEL HEATER SERVO. REMOVED OIL/FUEL HEAT EXCHANGER. INSTALLED SERVICABLE OIL/FUEL HEAT EXCHANGER. INSTALLED SERVICEABLE FUEL HEATER SERVO. REF AMM 73-11-07-400-801-F00 AND AMM 79-21-02-400-801-F00. IDLE LEAK CHECK TEST 3A PERFORMED AND NO LEAKS WERE NOTED REF AMM 71-00-00. ETOPS SIGNIFICANT SYSTEM AND COMPONENTS REF ETOPS MANUAL E07-00-03 73-11, 73-11-07, 79-21 AND 79-21-02. ETOPS SIGNIFICANT SYSTEM OPS CHECK GROUND VERIFICATION SATISFACTORY.