Sorry, confusion with series K, not N
No brushes or springs they are ac trucks
Check brush and springs in pump motor.
If this is badly, clean off the motor pump and remplace parts (brush and springs).
Pump shaft snapped on second truck
Pump code 57 turned out to be pump motor encoder bearing.
Next truck has no codes hyd wont work pump motor turns, but slow.Changed DSP card, inverter,logics controler no change.Voltage from inverter to motor 8.9v.Hardly any change when lever is pulled no change during steer.Sent to shop will be working on it in a few days.Any help would be great.