Hydro test ?
 

I Have the 147 tore down, and as my wife says I cant just leave stuff alone, so it has begun. I'm going to go ahead and do a quick resto, but I want to put a ported hydro in it. My question is ONE: is there a way to test my ported hydro before I put it in? and TWO: is there a manual, video, or post to help me out in case I have to dig in to the hydro?:bigthink:

You shouldn't need to open it up. Unless necessary, just clean the outside. All but one seal can be replaced without opening it up.

Hydrostat is covered in the chassis service manuals.

You can hook up a drill to the input shaft and spin it to test. Make sure you spin the drill in reverse.

so by using the drill, am I just testing for pressure?

Well..... what are you wanting to test?? Pressure? Or that is spins the axles..... ???

Hydro so very seldom fail that I don't get too worried about "testing" them. Put new fluid and filter in it, pull the rear diff cover, flush it out, pull the axles, drill the holes, clean the outside and replace any leaking seals and put it in. That's what I'd do.... but that's me. If it makes you feel better to spin it and see that it moves/makes pressure, then that's fine too. I'd still flush and do filter and oil first.

I just ask because i got it with the purchase of my 782, the PO said he didn't know if it was good or not. I just wanted to make sure before I put it in.

Are you going to take it off the rear it's on and install it on the one from the 147? Or just swap out the entire rear end?

It's just the hydro, not on any rear end.

The chassis service manual has detailed instructions for dis-assembly and reassembly of the hydrostat. If you have one on the bench, and you follow the manual instructions EXACTLY you can take it apart, inspect/clean, replace gaskets and seals, and put it back together. It is not a task for the faint of heart or mechanically dis-inclined. But it's not rocket surgery either.

I've done this to 4 or 5 units. Had one that was destroyed internally so I took it apart out of curiosity. (had nothing to lose, I figured). After that, I started going through them as part of my restoration process. A couple of the others had one or a few pistons that were plugged or sticking. Was able to return them to service successfully.

Keep your work area immaculate, keep track of the parts and where they go, and do not mix them up. Some look nearly identical, but put back in the wrong place or turned around, and it won't work. Be careful not to pinch the charge pump "O" ring on installation.

The service manual is actually very good on this topic.