Hi guys,
I know my answer is very late, maybe too late. But the answer is quite simple: you can buy a new pump directly from STC Schwab Technologie-Center in Germany. How come? Well, Sauer discontinued to manufacture the SIRO type pumps a few years back. But the manufacturing of these pumps was held up by a small company called Schulz Technologie-Center. They went bankrupt last year and the successor company is now called STC Schwab Technologie-Center. They are the same team with the same products, just a new owner. So where is the difference? They now serve the market directly (this was formerly done by a trading company, only). Do they ship to Canada and the US? Yes, many of their products go to those countries. Do they speak English? Of course, else you wouldn't be reading this. How about spares? Yup, they send those out, too - anywhere in the world.
How can they be contacted:
www.Schwab-T-C.de or +49 4392 9124-30
Hope this little background helps.
Joe