Might be late but a few things to consider. 1 is that with the engine shut down, you will only get a few pushes of vacuum assisted brake and then with the vacuum depleted the pedal will get considerably harder to push. 2 was it the same at all wheels? crap in the calipers could be acting as a check valve or even the brake hose can possibly but less likely cause this. If the bleeders are nice and clear you should be able to do what I prefer after 20 years of doing brakes. I remove the master cap, suck out as much fluid as possible, fill and open a bleeder starting at farthest from master and let it drip till it comes to clear fluid. repeat, moving closer to the master. If bleeding requires pressing the pedal, never, ever push it more than half way down. Pushing into unused territory that could be coated in residue could cause damage to the master. If replacing components, I still do the same but let it drip till no bubbles emerge and gently pump the pedal half way or less till it begins to firm up and rebleed. Do this a few times until no air emerges.
