Can you use automotive power steering fluid in a boat

Whether you are a boat aficionado or simply starting out in the boating world, understanding how your boat’s steering works is actually really important. Unfortunately, many do not worry about power steering until there is an issue. You need to familiarize yourself with your boat’s power steering and the maintenance that it needs. 

Most powered boats utilize power steering systems. These systems provide boaters precise steering from the helm while being less labor intensive and increasing accuracy at all speeds. Power steering systems for boats can be hydraulic or electric, depending on the size and class of the boat.

Power steering is something that you are probably familiar with from your car, but boat power steering does differ in many ways. You will want to continue reading to better familiarize yourself with how to care for this power steering system and some common issues that may arise. 

Power steering in most boats is very reliable, but issues are bound to occur at some point. It is important that you understand the basics of this system and how your boat is steered. In essence, power steering in your boat will determine your boat’s course when the steering wheel is turned and should be regularly maintained for proper steering. 

The steering wheel itself is part of something called the helm, this will connect to the mechanical, electrical, or hydraulic system that your boat utilizes. We will further jump into some of these various systems, regardless of the system used, you will want to understand the various parts. Each steering system will consist of a wheel, helm, steering cable, and cable connectors, which will link the steering wheel to the engine. 

A hugely vital piece to all of this is the helm, which connects the rotary motion of the wheel to the propeller. If your helm malfunctions, your propeller will no longer move with your steering wheel and your boat will not go the desired direction. Most helms are a rotary type, but yours may vary, depending on the type of boat you have or plan to purchase.

What is the Difference Between Hydraulic or Electric Power Steering?

For most power steering capable boats, there is one of two systems used: hydraulic or electric. These differ slightly but achieve proper power steering in marine vehicles. The main similarities and differences between these systems are:

Hydraulic Steering Systems

There are actually several types of steering that you can find in most boats, but perhaps the most used type of power steering is hydraulic steering. These capabilities can actually be added to boats that may not originally utilize hydraulics. You can find hydraulic kits that can be added to boats to amp up your horsepower and improve steering. 

These hydraulic systems are most often used on mid to higher horsepower motored boats. They can power larger, higher powered vessels. However, compared to other forms of steering, hydraulic steering can be driven super smoothly with a slight turn of the wheel. 

Depending on what you are looking for, hydraulic steering systems can be good if you are worried about corrosion. They often have fewer metal parts, which makes your boat more resistant to corrosion. 

Electric Power Steering

Technically, this style of steering is also a hydraulic system but does not use an engine driven pump. This power instead comes from a standalone electric motor. These power steering systems will vary in design depending on your boat, but they are often found on large center console boats that are powered by multiple outboards.  

Compared to our previously mentioned hydraulic steering systems, these electric systems are found on sportfish boats most often. They use a hydraulic pump or an on-demand electric motor pump. The only major difference between these two styles is the response time, which is slower for this style steering.

Larger sportfish boats often use electric power steering that runs constantly instead of the on-demand style. With these constantly running systems, a high-pressure hydraulic steering oil is pumped to the steering system consistently while it is powered on. 

This is different than the demand system because it will always be off until the helm wheel is turned. When turning the wheel, a trigger is engaged which allows the hydraulic system to turn on the pump motor. Since there are more steps, the response time is lowered. 

Parts of the Steering System 

Before we jump into the care of your steering system, let’s talk about the various parts of these systems. Identifying these parts can help you understand the maintenance and what controls your steering. You will want to look over your boat and identify these main areas of the hydraulic system: 

• The Helm – The helm is made of a hydraulic pump and valves, with this pump being activated when the steering wheel is turned. The helm is what takes the rotating motion of the steering wheel and converts it into a push-pull action on the cable. Essentially, this causes the rudder to move to the left of the right. 
• The Hose – This hose is used to carry fluid from the helm into the cylinder and back. 
• The Cylinder – The hose connects the helm to this cylinder, and it moves when the fluid is pumped from the helm. The cylinder is made up of a ram, board cylinder, and various hardware. 
• The Steering Wheel – This is of course a major part of the system and is what you utilize to control boat movement. The steering wheel will have cables that connect it to the helm and ensure that your steering movements lead to boat movements. 

Which Form of Power Steering is Better?

As you can probably tell, the type of power steering your boat will utilize will rely heavily on the type of boat you have and your personal needs. Faster, larger boats may need a more traditional hydraulic system that can have quick reaction time. While those who plan to use their boat for fishing primarily may do better with an electric system. 

Regardless of what your boat has, you may want to upgrade your power steering or replace what you currently have due to age. There are hydraulic steering kits that you can purchase and install or have installed in your boat. Some of the best hydraulic systems you can find online are:

Mophorn 150HP Hydraulic Outboard Steering Kit 

A super great kit that offers 150 hp and contains everything that you need to steer your boat properly. Allows for easy installation if you plan to do it yourself. Also, features a built-in two-way lock which can help eliminate any rebound torque. 

Woqi Za0300 Boat Hydraulic Steering System 

You can easily front mount this system and it features everything you need to work for a variety of boats, including all mounting hardware. You want to look over the specifications for your specific boat, but this is a great option for a large range of different engines and boats. The system fits motors up to 150 hp. 

Domestic Baystar Hydraulic Steering Kit Hk4200a

You will get everything you need to replace your steering system with this kit, including the steering fluid and all components. The system is made to fit even narrow splashwells, which can be tricky with some boats. This system once again works for horsepower up to 150.   

Seastar Pro Hydraulic Steering Kit

Seastar is a major name in the marine world and this hydraulic steering kit is made of quality materials and is extremely easy to install. It works for boats that travel up to 75 miles per hour and provides maximum control. You will get everything down to the screws and hardware to install this quality kit. 

Hydrodrive Outboard Hydraulic Steering System Till 90HP Mf90w

This is a premium steering kit that has an output force of 236Kgf and comes with a three-year warranty! The system is easy to install and works well for engines up to 90hp. The torque for this system is 50Kgm. 

Do Boats Have Power Steering Fluid?

If you are familiar with power steering, then you probably recognize that power steering fluid is a necessity. Just as automobiles need this fluid, so do boats. While the fluid for these vehicles is quite different you will need to monitor and eventually replace your boat steering fluid routinely. 

Power steering systems in boats are sealed, which means they should not lose fluid. However, many boats will lose this fluid over time due to minor leaks, which will need to be inspected. Regardless, the fluid will need replacing eventually because it will become dirty and less effective over time. You can do this replacement process yourself or take it to a trusted boat mechanic to do maintenance work.

Boat power steering fluid is actually formulated with special viscosity stabilizers, anti-wear agents, corrosion inhibitors, and anti-foaming agents that work specifically in boats. The best oil that you can use in these systems are those that meet MIL 5606, but other fluids can be used in an emergency. If you are unsure of which power steering fluid to use, you will want to see what your boat manufacturer recommends. 

How to Check Power Steering Fluid?

As with any boat maintenance, if you do not feel completely comfortable with working on your boat yourself, you should consult an expert. However, checking your power steering fluid is relatively simple if you know what you are doing. You will want to locate the helm of your system and remove the vented cap on the hydraulic reservoir. 

Take a sample of the hydraulic oil and examine it for usage. Good hydraulic oil should be mostly odorless, lighter colored or even completely clear. However, used hydraulic oil that needs replaced will be darker or even black and have a smell. 

If your hydraulic steering oil has any dirt or contamination, it will need to be flushed and replaced. Unfortunately, abrasive dirt can kill your system quickly and should be removed once noticed. This dust can enter your system in a verity of ways, even from the very beginning when hoses are cut, during initial installation, or when fittings are added. 

If you are purchasing your boat new, you will want to have the steering system flushed before any final hydraulic oil goes into the tank. Regardless, your boat fluids will need to be flushed and replaced every five years, along with bleeding the system for air bubble removal. You can do this yourself or you can hire someone to do this for you. 

How do You Know if Your Boat’s Power Steering Fluid is Low?

When you check your power steering fluid, you may notice if it is low or not. However, there are ways to tell if the steering fluid is low without ever opening your tank if your system is not working properly. To do this in a classic hydraulic system, you will want to turn the wheel all the way over the port, then to the starboard, and then back to the port again. 

If your steering wheel turns easily and the engine does not have hesitation, your fluids are probably good to go. However, if your wheel has any unpleasant sounds when going from one side to the other, you may need to add some fluid. As mentioned, these fluids do not simply disappear, so you will want to find where the leak is occurring and make the proper repairs.

How to Refill Boat Power Steering Fluid?

Refilling your power steering fluid is not overly challenging but does require some concentration and proper knowledge. You will want to get hydraulic fluid that works with your boat and meets the standards of your specific boat brand. Most manufacturers will have a recommended steering fluid that you should use, which is something to take into consideration. 

You can also look into your manufacturer’s manual, like this example, for additional information on how to refill your steering fluid. Most bottles have some form of directions, but I recommend following these steps:

• Find the right fluid for your specific boat and read over all important information. 
• Locate the helm pump and begin by threading the filler tube into this area. Then thread the bottle of steering fluid into the other end of this filler tube. 
• Use a sharp object or pin to poke a hole into the bottom of the bottle, and then turn it upside down. You will essentially set up a system leading your upside-down bottle to the helm pump through the filler tube. 
• Next, turn your steering wheel hard to the starboard side of the boat. At this time, you will want to find the starboard bleeder nipple. This is why it is important to know the parts of the steering system, as you will often find this bleeder nipple on the steering cylinder. 
• Now, turn the steering wheel to the port side. This will pump in the air and pump fluid out of the bleeder fitting. 

You will want to continue this steering wheel process until you see a stream without any air in it. Once you see no additional air, close the bleeder nipple. 

If you do not plan or need to use an entire bottle of steering fluid, you can poke your hole on the side and not the bottom of the bottle. Doing so with a pushpin will enable you to put this pin back into the hole once you are finished. This can allow you to keep what is left in the bottle for future use. 

Common Issues with Power Steering in Boats

As mentioned, the power steering in most boats is very reliable and you will often not encounter issues. However, as with all things, boats can have malfunctions and you can experience issues with your power steering. The main problem here is that you do not want to be miles from land and have steering issues, which makes educating yourself on these issues important. 

In most cases, you can salvage a situation before you are completely stuck and steering rarely completely fails. You do want to take steps to keep yourself safe, no matter how reliable your boat is. However, some common boat issues you may experience and what to do if you experience them are:

Fluid Leaks

It is important to note one more time that steering fluid does not simply disappear and if your fluid is low there is a leak. Unfortunately, you will often not notice the fluid leak until it is too late. However, if you do notice visible fluid leaks in your hydraulics, this is a sign that you have air in your steering, and you should keep this in mind:

• You will want to check the shaft of the ram of your boat to see if it is wet, wiping it down if so. 
• Give it a few seconds and if you find it is damp again, you will more than likely have a leak.
• If you have a leak, you may need to replace your seals and leaks can lead to unwanted corrosion, which means the seals have to be replaced and the air will need to be bled out. 
• The difficult part of this is that almost any part of your hydraulic system can experience leaks and it can be hard to find a specific leak.
• While these leaks can be repaired, it can be challenging if you are out on the water when this happens.
• If you suspect you may have a leak, you will want to fix the issue, bleed the air from the hydraulic, and replace your fluids.

If you are uncertain you have a leak, simply bring along a bottle of steering fluid in your boat. You can top up the oil for smaller leaks and for a temporary solution. If you are out on the water, topping off the fluid can help you get back to land. 

Contaminated Oil

If your hydraulic system has clean, uncontaminated oil, it should run smoothly. However, if any contamination occurs, it can cause the whole system to fail. This can be caused by practically anything, including minor amounts of abrasive dirt.

As previously mentioned, this dirt or dust can occur when the hydraulic system is installed. If this is not noticed early on, the steering fluid will be added, and the debris remains. You will want to check your fluids for signs of this debris and replace it to avoid issues. 

Air in the Hydraulics 

Another common issue is that your steering will feel almost spongy, which is caused by air in your hydraulics. You will notice this if you are turning the steering wheel hard in either direction and the steering bounces back. This is a sign that there is air trapped in the steering which can make it unpredictable and can cause it to fail. 

You will want to bleed the air from the system to avoid this bouncy steering feeling. Steering fluid is specially formulated to have a high compression strength, but air compresses rather easily since it is a gas—this causes sponginess and bounciness. You do not want to be out on the water with unpredictable steering as this can be very dangerous. 

Play in the Steering

You have probably heard of play in the steering, as this can be an issue with automobiles and boats alike. This often happens in boats when there is a leak in the steering system. You will want to follow the similar steps mentioned above in the leak section, by checking the ram for wetness and looking over hoses. 

If you are noticing minor play in your wheel, it could be basic hydraulics. This style of steering almost always has some minor play. However, if you ever notice an increase in play in your steering, you will want to keep this in mind:

• Never use your boat if you are noticing a major play in your steering. 
• You should immediately get help with this issue or try to do your own repairs if you feel comfortable doing so. 
• Try bleeding air from your steering system and search for any leaks. 
• Make sure to fix any leaks you may find and replace fluids. 
• This should resolve these steering issues, but you may need to seek expert help if you are still noticing an issue. 

Reduced Response 

When you turn your wheel, your boat should react accordingly. However, this is an issue that can arise with power steering and you may notice a reduced response from your steering system. Quality hydraulic steering should be highly responsive, and your boat should show quick reaction when things are working smoothly. 

If you notice that your boat’s response time is becoming slower and slower, you can often credit this to low hydraulic fluids. This is because the hydraulic fluid itself transmits the motion from the wheel to the rudder. If there isn’t enough of it, you can get a slow or “lazy” response to wheel motion.

Once again, play in the wheel is most likely low fluids, which is most likely caused by a leak. If you are out on the water and notice increasingly bad play in the wheel, you may want to top off your fluids and get closer to land. When you are able, follow the steps above to look for leaks, bleed the air, and replace your fluids.

Drifting 

A final issue you may notice from your hydraulic power steering system is that your boat may begin drifting. If your boat begins to drift uncontrollably and is doing so without you changing your steering wheel or rudder, you clearly have an issue with your steering system. This is often caused through issues with the helm or the cylinder. 

You will want to start repairing this issue by, you guessed it, checking for leaks in your valves and cylinder. You may need to have professional help with these issues and have both your cylinder and helm serviced. 

What to Do if Your Power Steering Fails

Most of the issues mentioned above will not cause your steering system to fail completely. However, they can make it challenging to use your boat and should be repaired quickly if possible. Of course, if you are out on the water when these issues show themselves, you may find yourself in a situation where your power steering fails you. 

If you are in a situation where your steering fails, you will want to follow these steps to avoid getting stranded in the water:

1. Drop Your Anchor – This is an important step if you are no longer able to steer your boat properly. Your boat can easily drift in the water if you are not able to steer and your anchor will help you avoid drifting further from land or into areas you do not need to be. Essentially, this buys you some time to figure out what to do next.
2. Steer Your Boat with Your Emergency Tiller – Most boats have an emergency tiller that you can easily use to steer your boat if your main source of steering fails. You should make note of where your tiller is located, look over it regularly for any rust or issues, and know how to use it should an emergency arise. Depending on where you are boating, it can be difficult to steer with a tiller and can be a little obnoxious, but this is a great option if you have no steering otherwise. 
3. Call for Help – Once you are anchored, you have some time to figure things out and that may just mean calling for help. Most waterways have people routinely monitoring the water and you can call for a tow. This makes it important to have a cell phone, radio, GPS, and more on hand to get proper help if needed. 

Conclusion 

Now you know the ins and outs of power steering when it comes to your boat. Most of these systems use some form of hydraulics to power the steering, which does require steering fluid. You want to have these systems routinely maintained and a common issue you may notice are hydraulic leaks in your steering system.

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