Bumper and Mike thanks for the suggestions. Adding the automatic vent
to the top of the cap sounds like a good move. I have pumped the
reservoir full from the bottom and wasn't seeing bubbles, but maybe
there is a big one hiding and being able to push more volume sounds
like a reasonable start. I have a big syringe from the pet store
that probably holds 3x the capacity of the system, but the reservoir
at the top becomes the limiting factor. The garden sprayer is another
great tip.

The caliper is mounted near vertical. I may pull it just to orient it
better and eliminate that variable.

Thanks again for the suggestions.

Morgan