727 not pumping fluid

It sounds like you did your install part OK.
I just thought of something.Maybe the pump is pumping, just dumping it all back into the pan.Or maybe its not sucking it up.
I guess it wouldnt hurt to drop the pan and have a peak in there.Check that the filter is on right, the VB is bolted tight,maybe drop that VB and check that the TC control valve is assembled correctly and is not stuck, or has wrong spring on it. I would do this before I would drop the unit.Good hunting.