B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 219; Flight Crew Type 13000
Training / Qualification
Aircraft Equipment Problem Less Severe; Ground Event / Encounter Other / Unknown
Flight Crew Returned To Gate; General Maintenance Action
Aircraft; Human Factors
During pushback and early in the start of number one engine; the Pushback Driver reported a large amount of fuel streaming from the bottom of the engine. He sounded quite anxious. We aborted the start; ran the Aborted Start QRH Checklist; then shutdown number two and were towed back to the gate. The Pushback Driver showed me the large fuel puddle where we had attempted to start number two. There was another significant fuel puddle under number one at our stopping point with fuel streaming out the bottom of the engine cowl. We called MX Control and they asked if we were familiar with the five minute engine run to stop a cold day related fuel leak. We were in vague terms but this leak seemed excessive. After reading Bulletin 15-29 we felt we had acted correctly.MX Control had us call Contract MX out. The engine failed the leak test with the engine running and statically after shutdown. After that; Contract Maintenance did two static maintenance diagnostic tests that cycled engine valves followed by two five minute engine runs. After multiple valve cyclings from this testing the fuel leak was confirmed to be within limits and we departed after the logbook was signed off and passengers reboarded.I'm not comfortable with Pushback Crews who aren't trained trying to explain if a fuel leak is within limits. My cutoff given the emphasis on doing business taking the conservative approach is if the Tug Driver's voice goes up a couple of octaves it's time to have Maintenance check things out. In this case we all made the correct call.
B737-700 Captain reported the pushback driver alerted them to fuel streaming from the bottom of the engine. The flight departed after maintenance attention.