Exactly jim44. The company I work for we install reversible fans on our Cummins powered equipment. They come with their own vacuum pump and electrical connections. These fans are made for almost any type of ag/farm/construction equipment. The controls are adjustable for frequency of reversing the air flow to keep the rad's clean. And easy to install as well. Remove the old fan and install the new one, run one hose to the fan, mount the controller, and make a few electrical connections. They even have a switch so you can reverse the fan at will from the operator's position. All self contained.
No need to get off your piece of equipment and drag out a hose, air tank or fire up a compressor, leaf blower to blow off/out the radiator. Saves a lot of time and effort. Just drive and the system once set will do the work for you. B.