hydraulic steering issue

I recently purchased a used 23' Seaswirl with a 200HP evinrude and seastar hydraulic steering. The steering seems to have alot of play in it when underway especially when wanting to make a turn. Fluid levels seem to be ok.Funny thing is when sitting on trailer there is no play in steering??? Any advise would be appreciated!

Hawkeye

If there is a place to check air pressure make sure it has the correct amount of air. Some of the steering assisted units use air to help with the steering and to maintain the proper fluid pressure. The air port will look just like a valve stem and you can add air there..