D17- IV ~ Hydraulic failure

I have a D-17 series 4, and today I was using it with an implement that requires both hydraulic remotes and the hydraulic system just stopped working. It was not in any bind or heavy load at all. I was raising a cylinder & it just jerked a couple of times & stopped. Neither hydraulic remote nor the 3 point lift will even try to work. It seams as if is not pumping any fluid at all. You cannot hear of feel the relief valves opening or any other sign of fluid flow. The power director works fine, so that part of the system is ok.
   I was hoping that some of you that have more experience than me on this model might know of a common problem or the most likely place to start troubleshooting.
        I can start working through the system & probably find the problem, but no need to reinvent the wheel, when one of you with lots of experience, might have a good idea what the problem is.
     Any advice would be greatly appreciated.    Thanks!!

I check the hydraulic fluid with screw in dipstick / breather on the left side forward of the gear shifter. That was my first thought, but I checked the hydraulic fluid level and it is fine.

Would the power director work if the pump drive was damaged? I was under the impression that the power director used the hydraulic pump?
Thanks!

I'm guessing it broke the shaft or gear in pump.                  MACK

    Well I finally got off work early enough to work on thevD-17. When I removed the pump, I checked the pump drive system and thankfully it appears to be fine. Dissembled the pump and at first I could not see a problem. After a better look, I discovered that the main gear ( I think 245781) that is driven by the input shaft was spinning freely on the shaft. It appeared that it was silver soldered or brazed to the shaft. Was that how it came from the factory?
      More importantly, does anyone have a source for a replacement gear and a repair kit for that pump? Alternatively, if I can’t find a new gear/shaft assembly does anyone know where I might find a used gear or even a used pump? It is the dual gear pump on the later model Series IV.
      If that fails also, is the pump on a 170 or 180 the same?
      Thanks again. I really appreciate the help.

If you decide to go with a rebuilt pump Hietman Tractor Salvage in Wisconson does a really good job rebuilding. I had to replace my Hydraulic pump this winter on my 180. I had to send them my old pump for a core after they sent me one they rebuilt. They wanted $1300 which was also the best price I could find. It has worked excellent and I would deal with them again as they were fast and great to deal with. If you need a phone # for them let me know but, they have an internet site.

If I remember correctly, D17 pump has female splines, the others have a male drive shaft .                       MACK