I don't know what hydro you have but if it is a Sundstrand like the older cubs
you could have the charge pump on wrong.
They are made so one can use them with different rotation engines.
The pump can be rotated 180* to change the input rotation.
It will not pump if rotated the wrong way!
Sitting on the seat looking down you will see the charge pump housing with 2 bolts holding it on to the hydro. that "dogbone"(pump housing with seal you changed),
on 1 of those "ears" you will see the it has been ground/machined off.
Did you put that side back to the same side it came off?
That machined ear needs to be on the
right side of the tractor.
In other words your right knee as sitting on the operator seat.
if not, just remove the 2 bolts and rotate it, the "O" ring seal should be ok since it is clean and just replaced.
I do need to suggest that the area around the charge pump is clean and blown off of any contamination it might of gotten in reassembly.
Oh I do need to also mention you have 2 choices to do that:
#1: dissemble like you did before.
Or
#2 remove the 2 hyd. line nuts and move the lines away and then remove the 2
fittings in the hydro that the line nuts screwed onto,
then remove the filter, now you can rotate the charge pump.
Now if you didn't put the charge pump back on wrong:
Take your air hose and wrap a shop rag on the nozzle and put a little pressure in the hyd oil fill hole while it is running.
Some times this helps prime the system/pump/filter.
Now you don't want high pressure just as much as one can blow with their lungs ( About #3) max.
Note:
If the pump was installed wrong you normally would be given a reprimand of watching John Deere sales promotional movies in black & white,
but since there is considerable work involved in this redo we will give you a reprieve, just this once
