Small boat owners with medium and high power engines know that mechanical steering is a way to quickly fatigue the hands and lose course accuracy at high speeds. hydraulics It becomes not just a convenience, but a necessity for comfortable and safe navigation, and the lack of feedback and vibration allows the captain to keep the boat confident even in the face of intense excitement, when every gust of wind tries to derail the boat from its course.
The transition to hydraulic drive dramatically changes the experience of the control, making it smooth and predictable. However, the process of implementing this system requires careful selection of components and adherence to the installation technology, because hydraulics does not forgive negligence. Any mistake in assembly can lead to a system failure at the most inopportune moment, so the theory must be taken seriously.
In this article, we will discuss everything from the type of steering machine to the final pumping system, you will learn how to correctly calculate the length of hoses, why it is important to use marine components and what tools will be required for a good installation. Hydraulic steering It is an investment in your comfort that pays off from the first minute you go out on the water.
Choosing the type of hydraulic system for your vessel
The first step to modernizing is to determine the type of system that will suit your hull and transom. The market offers two main directions: integrated systems where the pump is built into the steering machine itself, and systems with a remote pump controlled by a separate unit. integrated systemssuch as popular series Hydraulic Steering from the leading manufacturers.
If you own a large boat or yacht, where the engine tiller has a significant stroke or requires control of two or more engines, you need a system with a remote pump. pressure It must match the power of your engine, otherwise the pump simply will not cope with the shifting of the steering wheel at full speed.
When choosing a steering machine, you should also pay attention to the type of mounting: front (on the bulkhead) or rear (on the transom), the wrong choice of mounting type may require a serious alteration of the cockpit or the installation of additional brackets.
It is also important to consider the existence of a system. Anti-Feedback (feedback protection) that quenches the propeller jerks that are transmitted to the humming machine, which is solved by springs in mechanics, and in hydraulics by specially designed valves inside the cylinder, and the absence of this function on powerful motors will make the control twitchy and unpleasant.
Components: cylinders, hoses and working fluid
The heart of any system is the steering cylinder, which converts the pressure of the liquid into the linear motion of the rod. When selecting this unit, it is critical to consider the cylinder volume and the number of revolutions from stop to stop. The standard indicator for most boat systems is 3.5 or 4.5 revolutions, which provides a balance between reaction speed and force at the tiller.
Why can't you use a car hydraulic cylinder?
Car cylinders have no corrosion protection, are designed for other types of rubber and do not have pressure relief valves, which can cause the hose to rupture when the steering wheel is locked.
Hydraulic hoses must be made of materials that are resistant to ultraviolet, salt water and abrasion. The use of conventional fuel hoses is strictly prohibited, as they quickly collapse under pressure and exposure to aggressive environments. Working fluid It also plays a key role: you need to use special oils with labeling. Automatic Transmission Fluid (ATF) or specialized salmon oils that do not lose viscosity at low temperatures.
- 🛑 Steering cylinder - the main actuator, is selected by the power of the motor.
- 💧 Hydraulic fluid - medium of force transfer, should be frost resistant.
- 🔗 Fittings and hoses - must withstand pressure at least 2-3 times higher than the worker.
- 🛡️ Protective housings prevent damage to hoses on the side or tackle.
Pay special attention to fittings. They must be made of brass or stainless steel. Cheap silhouine compounds can burst under pressure, leaving you without control.
Always buy hoses with a margin of length of about 10-15% - this will avoid tension during the shifting of the steering wheel and simplify installation.
Boat preparation and installation tools
Before starting work, you need to prepare the workspace and make sure that the boat's transom is able to withstand the loads of the new system. If you install hydraulics on an old boat, you may need to strengthen the transom or digest the motor mounting brackets. Toolkit It should include not only a standard set of keys, but also specific devices for working with hydraulics.
You'll need a pipe cutter or a very sharp knife to trim the hoses neatly, because the ripped edges will cause the joints to leak out, and you'll need a set of tightening keys to keep the fittings from breaking the thread on the soft brass elements.
☑️ Preparation for installation
It is important to determine the route of the hose laying in advance. They should not rub against sharp corners, bend over or be in the heating zone of the exhaust system. Often, for laying it, the skin of the side or deck elements must be dismantled.
How to protect hoses in places of passage through bulkheads?
Use rubber sleeves or corrugated tubes so that the edges of the hole do not cut the braid of the hose when the boat vibrates.
Don't forget personal protective equipment. Hydraulic oil can cause irritation when it hits the skin, and at high pressure, the jet can damage the skin. Work with gloves and glasses, especially during the pumping phase of the system.
Step-by-step instructions for installing a steering machine
Installation begins with the cylinder itself being mounted on the motor bracket or transom plate, and make sure that the cylinder rod runs parallel to the transom plane and does not touch any foreign objects at extreme positions. brackets must be tightened with the force specified in the instructions, with the mandatory use of the thread fixer.
Then you have to lay the hoses from cylinder to pump (or tiller if the system is integrated), and try to make the track as short and straight as possible, avoiding unnecessary loops.
It is critically important not to twist the hoses when connected - this creates an internal stress that will lead to the braid rupture under pressure.
Connecting hoses to fittings requires care. It's best to lubricate the carvings slightly with oil for better sealing, but don't use a sealant on threaded parts that come into contact with the oil unless specified by the manufacturer. Puffing is done with two keys: one hold the fitting body, the other twist the nut.
After mechanical assembly, check all joints for visible defects. The hose should be free, without tension. If a draw-out pump is used, it is mounted in a convenient place, protected from splashes, but accessible for maintenance.
System pumping and removal of air traffic jams
The most critical step is to fill the system with fluid and remove air. Air traffic jams make the control "cotton" and can lead to cavitation of the pump. The process begins with opening the throughpass valves (if any) or disconnecting the return hoses for initial filling with rams.
Pour the oil into the expansion tank to the maximum level. Start slowly rotating the rummulus or steering wheel, watching the air bubbles coming into the tank. Add the liquid as needed, preventing the tank from being completely empty so as not to suffocate the system again.
To accelerate pumping, you can slightly tap on the hoses and cylinder so that the air bubbles break away from the walls and come up.
If the system is equipped with cylinder air-release valves, open them in turn when the steering wheel is repositioned. The procedure can take from 15 minutes to an hour, depending on the length of the hoses and the design of the system, the main thing is patience and constant monitoring of the fluid level.
Once the bubbles have stopped appearing, check the system under load. The steering wheel should run smoothly, without jerks or dips. If you feel soft at the end of the turn, then the air is still in the system.
Compatibility table and pressure settings
The right components are not possible without the specifications of the engine. Below is a table that will help you navigate the choice of cylinder volume depending on the engine power. Remember that the data are averaged, and for specific models there may be nuances.
| Engine power (hp) | Type of boat | Recommended cylinder volume (cc) | Max. Pressure (Bar) |
|---|---|---|---|
| 40 - 70 | Inflatable boats / Small boats | 0.9 - 1.2 | 35 - 50 |
| 75 - 115 | Aluminum boats | 1.4 - 1.7 | 50 - 70 |
| 130 - 200 | Medium-sized boats | 1.9 - 2.4 | 70 - 90 |
| 225 - 300+ | Large boats/Yachts | 2.8 and higher | 90 - 120 |
The pressure adjustment in adjustable pump systems is done by rotating the adjustable screw, and too high pressure will make the steering wheel heavy, too low will prevent full force from developing.
What if the wheel becomes tight after winter?
It's probably thickened, check the viscosity of the liquid, and if necessary, replace it with a less viscous one, or let the system warm up.
Don't forget that oil The system also affects how it works, and when you replace the hoses with longer ones, you may need an extra volume of liquid that is not always included in the standard kit.
Maintenance and typical faults
The hydraulic system requires minimal but regular maintenance, and the rule is visual inspection before each season, looking for traces of oil leakage on fittings, scuffing on hoses, and corrosion on metal parts. Any leakage detected must be eliminated immediately, as fluid loss leads to control failure.
Among the typical problems, we can distinguish the wear of the glands of the rod, which is manifested by a constant decrease in the level of fluid and oil stains around the cylinder. There are also problems with the valves if dirt or water enters the system. The water in the hydraulics causes corrosion from the inside and changes in the viscosity of the oil.
- 🔍 Check the fluid level in the tank regularly.
- 🧼 Clean the cylinder rod from dirt and salt after each fishing trip.
- 🔄 Change the hydraulic fluid every 3-5 seasons.
- ⚠️ Attention: Do not use WD-40 or solvents to clean the rubber parts of the system, they can destroy seals.
If you notice that the steering wheel has started to "float" or is not holding its course, check the presence of air in the system or wear of internal valves. Timely replacement of seals (re-kits) is cheaper than buying a new cylinder.
⚠️ Attention: If you find cracks or bloating on hydraulic hoses, replace them immediately. Operation of the damaged hose is prohibited and life-threatening!
⚠️ Attention: Dispose of waste hydraulic oil only in special reception points. Pumping oil into a reservoir is strictly prohibited by law and causes irreparable harm to the environment.
Frequently Asked Questions (FAQ)
Can I install hydraulics on a 30 hp engine?
Technically, it's possible, but economically and physically impractical. At these facilities, the tiller force isn't yet strong enough to require hydraulics. The mechanical drive will be cheaper, easier and easier to maintain. It makes sense to put hydraulics starting from 40 to 50 hp when the fatigue of the hands becomes noticeable.
How often should I change the hydraulic oil in the boat?
The recommended frequency of replacement is once every 3-5 years or if there are signs of contamination (occurrence, presence of water). If the system is sealed and not opened, the oil can last longer, but preventive replacement will prolong the life of sealants.
Why did the hydraulics become very tight after the installation?
Most likely, there were air plugs in the system that were not removed during pumping, and the cause could be overbending of hoses, using too viscous oil at low temperature, or improperly adjusting the pump (if it is adjustable).
Can I use the car brake fluid?
Brake fluids (DOT-3, DOT-4) are hygroscopic and can damage the rubber seals of the boat hydraulics, which are designed for oil base, which will cause the cuffs to swell and the system to fail.