January 03, 2019
Among upgrades that you can do to your boat to enhance your time on the water, the biggest bang for the buck is replacing a cable steering system with a new hydraulic steering system. This will make your vessel safer to operate and at the end of a long day, you'll have less fatigue from not having to wrestle with a cable-driven helm. If you have an older boat that was originally powered with a two stroke outboard and you repower it with a new four-stroke outboard, your existing cable steering system may not be up to the task. The added torque of a four-stroke outboard may prove to be too much for the cable driven helm to handle.
A hydraulic steering system is really quite simple. It consists of a pump, which is the helm, a pair of high-pressure hoses and a cylinder that mounts to the outboard engine. A steering wheel mounts to the helm pump and as you turn the wheel you pump hydraulic fluid through the hoses to drive the cylinder that rotates the outboard engine. The helm pump is equipped with a valve which prevents outgoing fluid from returning along the same hose. It also allows the operation of steering systems with two stations, like having a tower on your boat where you can drive from the upper station. It is important to choose a hydraulic steering system where the pump is sized correctly for the cylinder. Helm pumps have different capacities of oil moved with each steering wheel turn. The number of starboard and port turns is determined by the ratio between the cylinder volume and the pump capacity. The ratio of 4.2:1 seems to be a good average for most pleasure boats. The steering wheel will turn 4.2 times before the cylinder will completely turn from one side to the other. A system with fewer than 4 turns is not recommended, as it will need more effort to turn the steering wheel. A system requiring 8 turns or more is not good because the response is too slow.
Once you've operated a boat with hydraulic steering, especially while docking, the benefits are clear. A couple of companies produce a hydraulic steering system kit in a box complete with all of the components you would need. The only choice you have to make is the length of hoses you need to make it from the helm aft to the engine. The helm comes sized to the cylinder and the kits come with easy to follow installation instructions, even hydraulic oil.
Many steering system configurations can include multiple steering stations and dual or triple cylinders. For the purpose of this article we'll focus on a boat that has a single helm station and a single outboard using a front mount cylinder.
First, start by determining the length of hoses you will need. Measure from the helm to the center of the outboard taking into account routing of the rigging and some slack for movement of the cylinder from side to side. Unlike a cable-driven steering system, it's okay to have a little extra hose, simply tie it up in the bilge area or under the console. Armed with this information you can choose the correct kit for your particular boat. Removing the old cable steering system, start at the helm. First remove the steering wheel, then the bezel, helm mount and helm. Loosen the nut that holds the cable in the helm and rotate the shaft on the helm until the cable comes free. Next, loosen the nut that secures the cable to the tilt tube on the outboard and pull the cable out of the tube. It's far easier to pull the old cable out toward the stern; the outboard end of the steering cable has a solid stainless steel shaft that doesn't like to bend around corners of a rigging chase. Prior to pulling the cable out, tie a strong piece of small diameter rope to the helm end. Be sure it's long enough to reach the transom. It will be your pull string to pull the two new hydraulic hoses forward.
Now that the old cable system is removed, follow the installation instructions included with your hydraulic steering kit. Carefully follow each step of the bleeding instructions when it's time to add hydraulic oil and purge the system of air. Any shortcut here will result in sloppy steering and a real mess when you have to bleed the system a second time, the right way.
When you're used to cable steering, turning the wheel with hydraulic system feels funny, like nothing is happening. Don't worry, the third or fourth time you turn around to see that your motor really is turning, you'll wonder how you ever got along without hydraulic steering.
Removing the steering wheel from the old cable helm can be accomplished without the need for a puller. Loosen the nut, which holds the steering wheel onto the helm shaft, until the top of the nut is flush with the top of the helm shaft. This will protect the threads on the shaft. Pull on the steering wheel to apply upward pressure and at the same time hit the top of the nut with a hammer.
The shaft is tapered and once the steering wheel moves the slightest bit, it will come free. Before pulling the new hydraulic hoses forward, include a small nylon cord that can be used at a later date as a pull string for wiring, transducer, etc.
To help the hoses slide through the rigging chase, coat them with a thin layer of cooking oil. This will allow them to slide easier and have less chance of chafing any wires by friction. FS
First published Florida Sportsman January 2015