It's been a while since I put a 756 together and there was something about those hinges and pins that are different than the other Bennett pumps. If I remember correctly there is a hinge stop on the hinge that only lets the door open so far. If I remember correctly the hinges had to been open half way and the door Parallel to the pump and then put on the hinges. I could be wrong. I had to take a hinge off and try it on the door to figure it out. Richard