8356 Fisher Belt Drive Cable Operated Plow Pump

Here is a Fisher Pump Assembly (part # 8356.) These are genuine Fisher parts. Fisher uses this pump on under hood belt drive systems. This would be used with an external fluid tank. This one has 1 port on the side and 2 on the back. 

They had 2 later model pumps that had the ports on the sides on the pump and not back - the cast iron version was 21981 and the aluminum one was 21220.

In the back of these pumps it is stamped 1002593.