Thank you so much!! I will start over on the pump and watch the video closely.There's been some confusion about the build of your pump. If it's the same as the one in the video, it doesn't have a rack and segment as was being discussed earlier, but the fundamental problem appears to be the same.
In your video at 49:30, see how he's lining the pegs up with the cutouts in the rack? You either have this wrong or you have a plunger 180° out, time ref 34:00.