John Deere F935 Just stopped moving

[treedigger]

I have a F935 that just stopped moving and lost all hydraulics while mowing.It has a Sundstrand Series 15U transmission. It was not losing power it just stopped while going from forward to reverse. The mower was working fine and then just stopped moving. At the same time the steering stopped working and the lift for the deck stopped. Engine runs fine and pto works. Drive shaft is turning the charge pump. I have taken the charge pump out and checked it. When I did a charge pump pressure test it only has about 15lbs. While it was out changed the seal, bearing, o-ring and pin. Inspected pump for wear and damage and everything looks fine. Checked and cleaned charge, implement and steering relief valves. I also changed the filter. I still have no hydro. Like I said everything was working great right up to the time it stopped. I think something come apart in the transmission itself. Any help or Ideas would be appreciated. Thanks, Craig