Determining if a Hydraulic Steering Cylinder is Balanced or Unbalanced

One major factor when purchasing and installing an autopilot is to know if the hydraulic steering system is balanced or unbalanced. An unbalanced system may require a kit sold separately (depending on the pump needed).

Balanced or unbalanced systems differ by the amount of hydraulic fluid it takes to steer in one direction than the other. A balanced system will use the same amount of liquid to turn in both directions. An unbalanced system will require less fluid to steer the engine or rudder in one direction than the other. Examine the steering cylinders to identify the type of system on a vessel:

• Balanced cylinders have a rod extending from both ends of the cylinder

• Unbalanced cylinders have a rod extending from only one end of the cylinder

Two unbalanced cylinders can make up a balanced system if the unbalanced cylinders oppose one another. See examples below

Another quick test is to steer the boat hard-over from port to starboard and count the number of turns. Count the number of turns it takes to go from hard-over starboard to port. If the number of turns differs considerably in one direction from the other, the system is unbalanced. A balanced system will require the same amount of turns in either direction.