With the parking brake engaged, start the engine and move the lever like you would do to make the loader move and see if the engine pulls down. If the charge pressure light is not on, then it is safe to conclude the pump is turning since the charge pump is in the right hydro pump. When you say right, you mean as you are sitting in the seat facing forwards, correct? I suppose it could be a bad servo on the pump, but not too likely. The most likely cause is either the hydro motor or the gearbox. If the engine does not pull down and you want to isolate the pump from the motor, remove the two large hoses from pump and cap the fittings on the pump. Now restart the engine and slowly stroke the lever. It should definitely pull the engine down now. This will not damage anything in the pump since the relief valves are in the pump. If the engine does not pull down with the fittings capped, then you have a problem in the pump.