Scott, here is a supplier for Harig products but the prices aren't pretty. I don't know of any place to purchase used parts. Possibly you could adapt some other type pump that is not as expensive. http://www.trutechsystems.com/harigstore/home.php
I have just bought a clone of a harig and they put a hand type pump like those used on a milling machine and it works fine give a few pumps and thats it. Others are to expensive .keep sump clean and filter oil and reuse.