Hyd Steering

[tlb888]

Had a little issue on the water today and need some advice, which I am sure I can get here. Steering worked fine and started getting stiffer as the morning went on and got to where you could barely turn it. Limped it back to the ramp. I checked everywhere I could see at the time for a leaking line but haven't found it yet? What kind of fluid does it take and any suggestions would be greatly appreciated. By the way we did get our limit of 6 fish so it was still a good day.