myself, I would pull the dist and intermediate shaft. If nothing is obvious one could try priming witha drill or speed handle as suggested. DO NOT FORGET it's CCW rotation.
If still nothing one could try the filter. I would not discard the filter but bag it for inspection if needed.
At that point, you can either
A. Remove the pressure relief valve and try cleaning it and the bore. Reinstall and try priming again
or
B. Remove the pump for inspection.

We had one years ago that hung the relief valve open. We removed the pump ( 340) took the cover off and the valve was stuck open. My buddy used a small screwdriver and just barely touched the valve and it snapped shut. Apparently a microscopic piece of something hung it open.
Keep us posted beer

Last edited by TJP; 03/14/21 08:29 PM.
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