Jerry, I think I learned about all there is to know about those pumps the hard and expensive way (same way I learn lots of things). A friend and neighbor had a daughter and boyfriend living in an old house that he owned. The boyfriend was in some kind of lawn care business, but then suddenly left the state, leaving some of his equipment behind, including a sprayer/washer rig with a 3 hp Briggs engine, 25 gallon tank, and Hypro pump. So it had been sitting behind that old abandoned house a couple of years when he started cleaning up the place and asked me if I wanted that thing. I put a carburetor on the motor and got it running good. The pump was seized so I took it apart and went and bought a new roller kit which didn't help. So I bought a new pump; first one I got was set up to turn the wrong direction so they gave me another one that turned the right direction. That was when I learned that you can simply open them up (4 bolts) and turn everything around. On a tractor PTO, you need them to turn one direction and on that rig I had, they need to turn the other direction. With a little experience, I found that it doesn't take much corrosion internally to make them seize, so after awhile that new pump seized. I simply took it apart and cleaned it in my glass bead blaster cabinet (like a little sandblaster) and it was good as new. The old original pump probably would have been fine if I'd done that. So after that, before I put it away, I filled it with antifreeze. Next time I went to use it, I dumped the antifreeze, used the rig, then reused the antifreeze to protect it until I needed it again.
Of course, I certainly don't know about your neighbor's pump, but suspect he could open it up and fix the problem quicker than he could drive to wherever he bought it to exchange it.
