Watch that wear pad (bushing pad) under the crank in the CP3. If you took the aluminum face plate off without something holding the crank down in place the wear pad ears (3 of them) will usually turn and youll never get it together properly (with out free turning with the face on). The wear pad will need to be realigned. You either need to pull the crank to do it or have a special tool to realign it (I made one). I had to do this quite frequently for these pumps a few years ago. There is a thick shim with a taper on it that slides down into place as you rotate the assembly to hold the plungers up in the bores to relieve the pressure off the crank cam so you can pull it straight out. Made one a few years ago. Cant remember the thickness exactly. I think it was like .070 or .090 thick. Made it to go 3/4 or so around the inside of the bore. Worked like a charm. It was some ridgid stuff. Hope this helps.
I remember you telling me step by step over the phone how to get the cp3 pump back together, after i decided to take the front cover off to plug off the dual feed line fittings on an ats pump. got it back together though!