Hydraulic steering issue
 

After my last time out, I noticed a little power steering fluid in the bilge by the starboard motor. Checked every line and the cooler for evidence of a leak and found nothing. Fluid wasn't sprayed everywhere. The only evidence i found was a few drops on the outside of the reservoir. When I start the stb motor, the fluid level drops down, then fills back up when i shut it off. Do i have air trapped in the system? Ran with cap off and turned the wheel to try and bleed it. Port side is fine.
Boat is a 353 formula , 525 x2 with latham steering.