The drawbar is hydraulically operated from a pump so does not require compressed air.
On the wall or the rear of the machine there should be a regulator and gauge.
6.5 Bar or 100 psi is about nornal but it should operate OK with say 40 psi even.
Do you have a copy of the maintenance manual?
I am looking for electrical schematics for the same machine and would be very gratefull if you could email me a copy to
mike@macontrols.com