Hydraulic Steering

Boat owners frequently call or come to the shop with hydraulic steering problems - turning the steering wheel and the boat is not responding. The problem can be encountered with both center console and side-mounted steering systems.

When this condition develops, it has usually been happening intermittently and/or growing steadily worse over a period of time. Quite often the steering stops working completely when least expected.

The problem is air entering the hydraulic system due to fluid leaking out.

There are two main areas to inspect on a regular basis to avoid this problem and these should be part of your regular preventive maintenance program.

There are shaft seals located in the end caps of the hydraulic steering cylinder. These seals are the most common source of failure. Sand, salt, or other debris building up on the shaft over time act as abrasives and eventually destroy the integrity of the seals and sometimes the shaft can be damaged as well.

The hydraulic lines connect to the steering cylinder via two 90° fittings on the body of the cylinder and these should be inspected periodically for leaks. We see these leaks occurring from the fittings becoming loose over time or sometimes bent due to contacting the transom while over-tilting the outboard motor.

Wiping your finger under each cylinder end cap and both 90° fittings will indicate a leak if a yellow film is detected.

The helm seal would indicate a leak (yellow film) either under the steering wheel or behind the console.

The fluid reservoir is located in the helm. There is a fill plug located just behind the steering wheel at the top of the housing. Removing this cap will allow the use of an applicator to screw in and fill the system using hydraulic steering fluid or, in a pinch, tilt and trim fluid.

Adding fluid will get you by for a short time but a repair must be done to correct the problem.

Washing the cylinder with soapy water while cleaning the boat will really help prevent debris buildup and a light application of Corrosion X (red) when putting the boat up is another great preventive measure.

Always keep a bottle of fluid and an applicator on the boat in a sealed Ziploc bag. This is good insurance in the event an emergency refill has to be done on the water.

We recommend Seastar Hydraulic Fluid # HA 5430 and Seastar Hydraulic Applicator # HA 5438.

Have a great fishing season.

Chris Mapp

Coastal Bend Marine
Port O'Connor TX