No valve blockMy knowledge of hydraulic motors suggests that the two larger lines will be pressure and return, and it's most likely reversible. The smaller line coming off the back of the motor will almost certainly be a case drain which will need to return to tank somehow to allow the internal leakage to bleed off.
Is there a valve block the two main lines go to?
More pictures would help.
Hey Canadian
how many couplings you have on your posi?
^ If it was made 'years ago and never run' there may be a chance of Bearing Failure near motor, if it feels warm _ only 'simple solution' I can see
** Accordingly, check the Oil Temp (if a gauge on unit/ or hands on hoses) to see that it is NOT seemingly heating up too much.. I doubt it really should get too hot running free as such _ Good Luck