Hi Rich, been looking around and it appears like the keurig only has one pump. but it does have plenty of tubes that could be kinked or blocked. I would open her up and do a good visual inspection, and test any possible leads.
I have also looked around the web and notice not many promising solutions, I would assume you have tried cleaning with vinegar. And actually if the previous owner was running hard water through it then that quite possibly mineral buildup could be the issue.
Good luck!