Some people are very ingenious.
I too made one of these pumps and ran it for a couple of years. Unfortunately the noise isn't the only down side. Previously they were available at most junk yards and you could get them either free or for pocket change. They appear to have stopped using them on US cars about 10 years before they stopped on Japanese imports which appears to have ended in the '80's. Hence, the parts places have been getting fewer and fewer calls for them and no longer have them as a ready inventory item.