Hydro quits in higher speeds

[Nhbalerman]

I am still having trouble with my NH 912 speedrower with the hydro like in the NH L35 and the L775 I tore it all down and replaced some broken parts and when I start it up only one side will work and finally the other side will work and it continues to work unless I steer it fast in either direction or increase the speed and it will quit and shift back to nutreul and work the lever back and forth and then it starts moving again just seems like it is not getting enough oil at the higher speed or when turning. The charge pressure id 90# at idle or increased rpm any help would be greatly appreciated. Thanks