Nice work, 13.5 is a little high, but the Skyworker may not care too much. If you start developing alot of little leaks, or the thing flys around like a carnival ride you may have to get a smaller pump, but run it for now.
First get you self a gallon or two of aircraft hydraulic oil. We use Diala AX made by shell. Run the upper boom over center from the lower controls so the basket is on the ground. Fill the little resevoir at the upper controls, and pump up the little primer at the upper controls. It should become hard to pump. Try your functions, you may have to repeat this several times to bleed the air using that little plunger. You also may have to crack the bleed valves at the lower control valve to let some air out. We use a pressure bleeder which attatches to the bleed valves at the lower controls. It is much quicker and gets all the air out.
If the plunger doesn't seem to be doing the trick you may have problems in the upper or lower control valves, when was the last time the unit ran? Give that a shot for now.