Hydraulic steering problem
 

Hi. I have an IMCO tie-in single ram hydraulic steering attached to a Bravo drive with the old type Saginaw control valve. When running the boat at higher speeds the boat does not steer straight, it "meanders" slightly. Further, I tried to move the drive from the outside with the engine running at idle and also fast idle (in neutral) and it was relatively easy. The wheel also moved. The gimbal is new and there is no or very little play in the steering, maybe half an inch at the most.

Is this normal? I would have thought that it should be more or less impossible to move the drive from the outside with the engine running. Could it be air in the system???