Landini 30

I removed the engine mounted hydraulic pump in a Landini 1-30h to put new seals in it as it was leaking. Reinstalled the pump and now it has no hydraulic function. I'm a mechanic but don't work on tractors much, I'm confident I asembled the pump correctly. The oil is just below the add mark but I didn't have any at my shop, will be adding some today. Has anyone ran into this issue before? I have experience with hydraulics but this is making me scratch my head

I’m having an issue with my Landini Landpower 165. The tractor starts and idles normally, but when I push the throttle fully, it only revs up to about 1300–1400 RPM and won’t go higher. Basically, under load it won’t provide more than half throttle. The accelerator pedal is electronic, not mechanical. Possible causes I’ve considered are: • faulty throttle position sensor or pedal potentiometer • ECU limiting or derating due to a sensor fault (e.g. boost pressure, coolant temp, fuel rail pressure) • restricted fuel supply (pump, filter, or injectors) • wiring issue in the electronic throttle system Has anyone here had the same problem with a Landini or similar tractor, or knows what I should check first?