4. Sufficient Tankage
The ideal rule of thumb for fluid capacity is three times the maximum flow of the pump, but it’s unrealistic. If you have a pump making 4 gpm at 600 rpm, it will make 16 gpm at 2,400, and a 48-gallon tank takes up lots of space. Instead, most shops use a 1:1 ratio but encourage owners to install an in-line cooler to keep temperatures in check and steering smooth.
5. Pump Potential
Power steering uses an engine-driven pump — either mounted on the motor or belt-operated — to open and close hydraulic cylinders. The pump needs a third reserve hose to return fluid to the tank. Typically, for a 30- to 40-foot boat, you’ll need a unit that pumps four gallons per minute at idle to maneuver around the docks. As engine rpm increase, so does the pump’s flow rate. A quality system has a diverter kick in at a preset flow rate to divert excess fluid back to the tank.
6. Steering Cylinders
The point of contact for the rudder, sterndrive or outboard in the system is the steering cylinder. Most boats under 40 feet use single cylinders. Outboard cylinders may push against the boat or just the engine, and offshore performance boats use twin stainless steel.Dual-cylinder inboard installations offer smoother rudder action versus a single cylinder.