Bench bleeding new MC, No fluid moving through rear outlet Options

[mankowski]

New 19mm ATE master cylinder is not moving fluid through rear outlet when attempting to "bench bleed." The MC is mounted on the car with ~5ft of tube from each outlet port back up to reservoir, with one tube in each of the two reservoir chambers.

Some fluid did pass through the rear outlet into the tubing at first but not even enough to get up to the reservoir, and now the fluid is stopped entirely. The fluid is moving fine through the front brake outlet.

It's my understanding that I should not be bottoming the MC piston out, but how far should I be pushing -- maybe further piston travel is needed? If so, I wonder why this be the case when the fluid from the front outlet is moving fine?

Or, is there more likely something blocking in the rear outlet or plastic fitting? But I can't imagine how that would happen in a brand new MC and bleed kit. (IMG:style_emoticons/default/screwy.gif)