As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ACCOMPLISHING TEST 3A-LEAK CHECK ON THE NR 1 ENGINE FOR HPTCC VAVE REPLACEMENT, FOUND LEAK COMING FROM SERVO FUEL HEATER. ACFT GROUNDED. REMOVED AND REPLACED THE NR 1 ENGINE SERVE FUEL HEATER IAW AMM 73-11-07-000-801-F00 & 73-11-07-400-801-F00. OPS & LEAK CHECKS OK.