Date: 202103
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Rain
Light: Night
Aircraft: B737 Next Generation Undifferentiated
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Airspace: Class C ZZZ
Aircraft component: Powerplant Fuel System
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Fuel Issue
Detector: Person Flight Crew; Person Maintenance
When detected: Aircraft In Service At Gate; Pre-flight
Result: General Flight Cancelled / Delayed; General Maintenance Action; General Release Refused / Aircraft Not Accepted
Contributing factors: Aircraft; Procedure
Primary problem: Procedure

Narrative: Fuel leak discovered prior to pushback. Maintenance says 'no big deal happens all the time.' So we ran an engine to see if the leak would seal and shut down and ran 70.20 QRH. Maintenance tells me leak is gone no drips. I opened my window and visually checked the engine and saw fuel leaking at an alarming rate from the bottom of the number one engine. FO (First Officer) and I went outside and measured the rate of drips and we recorded 175 drips per minute. Asked Maintenance why they told us the engine was not leaking; and they denied seeing any leak. We would have taken off with a major fuel leak had we not checked ourselves. Maintenance in ZZZ was pushing us to depart because they needed the gate. ZZZ Maintenance's overriding concern was obviously not for the safety of the passengers and crew. 8 fire crew surrounded the aircraft after the leak was discovered and they said they would not authorize another engine start yet Maintenance asked us to try again to start even though fuel was pouring out of the engine.


Second narrative: Just prior to engine start ground crew reported fuel leaking from Number 1 Engine. We performed QRC Fuel Leak. It failed. Logbook entry accomplished. Asked to do engine run. Got permission; coordinated with all; did 5 minute engine run. Shut down engine. Ground personnel said there were no leaks. Captain looked outside window and steady stream of fuel was leaking from engine.Captain and I went down to look at leak and count drops per minute. 175 drops per minute at that point which progressed later to a steady stream of fuel coming out. Fire Department responded with 2 engines. During the ensuing hours; MX (Maintenance) kept trying to get us to do another engine run. Fire Department said due to the amount of fuel leaking they would not allow it at the gate. We absolutely agreed. MX kept coming up to us with documents telling us this was OK; and if we would just do this engine run; all would be well.In spite of this; MX wanted to run a procedure for a 60 or 100 drops per minute engine leak. We were originally at 175 drops per minute and progressed to a steady stream. Clearly this procedure did not apply. Both Captain and I were very uncomfortable with all of this. Jumping back to the leak first being discovered and the need to do an engine run; MX attempted to get us to hurry up with the engine run because a 777 needed the gate. This was mentioned several times; to the point where the Captain became so uncomfortable he had to tell them to slow down; follow procedure; and focus on what we were doing. As the engine run resulted in an even worse problem; Captain refused the aircraft and we left the scene. Operations refused to cancel the flight for a considerable period of time. This delay was so bad; the Captain and I eventually left the airport for a hotel. Scheduling talked to the Captain and informed him we would be flying into our day off; a new part would be flown in; jet fixed; and we were scheduled for an MX ferry flight on the [Date1]. We got to aircraft only to discover no part had been flown in. Nothing had been fixed. MX had done several engine runs and said there was no leak. This was; in my career of flying jets for Company since [Year]; and having done many thousands of walkarounds; by far the worst leak I have ever seen. Something in the jet broke. We were told it would be fixed. Nothing was fixed. At this point; we had lost confidence in anything local maintenance was telling us because they were still trying to use a checklist; which they showed us; with very minor 60-100 drops per minute leaks. The part you see in the attached photo was not replaced. Nothing was replaced. We refused the jet again. Numerous attempts were made to get us to do a high powered engine run; which we are 1) not trained 2) there was heavy rain and standing water; making for slick surfaces; so we would not have done it under those conditions anyway. Captain refused jet; and due to the pressure put on us from local maintenance; we left airfield. Scheduling put us on a deadhead flight home the following day. Scheduling sent crew out on [Date2]; DH to ZZZ & MX ferry jet Aircraft X back to ZZZ1; even after no repair was made to this part.


Synopsis: B737 NG flight crew refused aircraft twice due to excessive fuel leak from engine.