Thanks. Good reading.
I started operating hydrostatic machines when I was 18. Don't laugh, it was a Wheel Horse tractor converted into a hydraulically articulated airplane mover with an oversized sun strand pump and no front axle. It was cantilevered with a rear steel fork for picking up nose wheels with a hydraulic cylinder operated lift. You sat backwards on the hood with the steering wheel between your knees. Anywho, I had to work on it once in a while.
Then around 1989 we bought that late 70's IH2500b tractor loader. It was HST. So I purchased all the manuals for that and got a pretty good understanding of how it worked.
Now we have the PT425. It's a beautifully simple machine. Just beautifully simple. And that's what I like about it. Almost as simple as my '70 Nova with the 230 L6 and three on the tree! :thumbsup: