Converting hydr. Motor to PTO drive on swathinverter????

Hi there, I'm new to the forum. 

Question: We have a Matador 7900 swath inverter, it runs the pick up via a hydraulic motor, it's own speed valve and is hooked into the tractors Hydraulic system.

We have the thing since quite a few years and it's all great, but the hydraulics on the tractor heat up too much with the swath inverter working for a period of time. Tried it with two different JD tractors, same story.

 

How much work would be involved to replace the hydraulic motor on the swath inverter with a PTO drive hydraulic motor. 
Is it 'do-able' and how would figure out which PTO drive motor would be equivalent to the hydraulic motor currently on the machine?

 

Or, how can we keep the tractors hydraulic system cool while running the inverter, if we can't convert it to PTO drive?

 

Thanks for your input. 

Converting hydr. Motor to PTO drive on swathinverter????