How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Joe Your Own Question
Joe, Marine Mechanic
Category: Boat
Satisfied Customers: 7251
Experience:  ASE, electronics, Marine mechanical and electronics, pwc, wiring, all around repair tech,
Type Your Boat Question Here...
Joe is online now
A new question is answered every 9 seconds

, I have a Mercruiser 350 Horizon. Serial 0M093415, and i

Customer Question

Hi Jason, I have a Mercruiser 350 Horizon. Serial 0M093415, and i am having trouble with the power steering.

I have owned the boat for about 12 months, and have done about 10 hours in it. It has about 300 hours from the previous owner.

The power steering has not worked since i have owned it. I thought the issue would be the pump. I borrowed a pump off a mate of mine who advises that it was working just fine when he removed it a few months ago, but this has made no difference. I am yet to pull the steering cable off, and will probably try this in the next day or so, however i wanted to start spitballing with you to work out my plan of attack.

The boat is on a trailer in my garage. If i hook my water up and start the boat, the power steering is clearly not working. However if i begin to turn the wheel left lock to right lock with a fair bit of speed, it feels as if it starts to get better. Then when i stop and go to turn it again, its bad to crappy.

When i do turn the sterring from lock to lock, i dont hear that typical loading up of the pump at each lock. However again - my mate assures me the pump worked fine when he removed it. He is a long time boat guy with great mechanical knowledge. Any suggestions?.

Ive been trying to work out if it could be the actuator. But ive heard a few people say these very rarely fail. II suspect the pump failed some time ago, and hasnt worked for who knows how long. What should i be thinking about next?. Assuming the cable is OK (which im not saying it is, im just thinking past that as part of my troubleshooting)......what do i need to think about.......

you nailed my bravoitis problem last time we spoke...........see if you can make if two for two :)



Submitted: 2 years ago.
Category: Boat
Expert:  Joe replied 2 years ago.
Hello and good morning Dave,

Thank you for your question, my name is ***** ***** I will be glad to assist you with your concern today.

I would start by removing the cable from the steering actuator and then turn the steering, it should turn easy side to side, if not then remove the cable from the helm unit and if still having a problem it is in the helm, if not then replace the cable (if binding) if neither are the problem then would need to check the belt tension not slipping on the pump and insure the pump is working also checking fluid is full and no trapped air as well as lines correct. It is true that it's not often an actuator goes bad, however it can happen and is usually in the tube, you can disconnect the actuator from the drive and (not in the water) turn the drive side to side to confirm it's pivot points are not the problem.

Turning hard lock to lock esp holding at a hard lock you should hear the power steering pump load up, if not there may be air or a bad pump or belt is too loose or not, however this can also happen due to the tube in the actuator and could also be a blockage/restriction in the power steering cooler.

It's pretty much a process of elimination and there are not many things to do just what there is to be done does require some hours of testing.

Thank you!

- Joe

Please rate my answer when ready. Bonuses are appreciated.

If for any reason you are not satisfied please reply back to me for further assistance to which I will be glad to help you. The rating system is only to rate me as an expert not the site or the product. If you have any problems for any reason please reply back and let me know.

Thanks again for using justanswer and have a great day!

If you need any further assistance you can reply back at any time for my help.

I'd be happy to answer any other questions you have even if not related.

Customer: replied 2 years ago.

thanks Joe. Today I will remove the steering cable and test it.

Im quite sure the belt it tight enough.

Can you expand on the removal of the actuator from the drive?. Im pretty sure I understand what you mean, but if you could supply me with a document to follow or refer to it would be appreciated.


Customer: replied 2 years ago.


OK - so I did a few tests today.

1) I disconnected the steering cable at the actuator end, and the steering is free and easy to turn. I can feel very very minor notching in behind the steering wheel, but all in all its extremely easy to turn. No issues turning it with one finger.

2) I disconnector the actuator from the sterndrive, and then manually moved the sterndrive from side to side. The action was very smooth and easy to move with no sign or feel of any binding or sticking at all.

3) I removed the actuator, to try and understand how it works. It seems to have a cylinder with a piston inside it (which I assume is where the fluid is either pushed or pulled in or out of, and another section that appears to be what controls the valves.

It appears as though when the motor is turning, and the is pressure running through the system, when the steering wheel is turned, it moves the valves section, which allows fluid to either pump into the piston cylinder, or vise versa. Not sure how accurate that is?.

I have attached link to a video I put on youtube showing me manually operating the actuator. Are there any tests I can do other than this to prove wether the actuator is working properly or not?

4) I have removed the power steering cooler and confirmed there are no blockages. Fluid flows freely through the cooler.

Look forward to hearing back from you.


Customer: replied 2 years ago.

Joe - any time of an answer soon?.

Expert:  Joe replied 2 years ago.
Good morning Dave,

My apologies for taking so long to reply back.

You can try lubing the tube inside the actuator but the problem is that the actuator usually needs to be replaced to fix the problem if the problem is not that the inside of the tube is corroded, if so then you can purchase a bursh end that connects to a drill which will clean inside the tube to which you can then lube it. The cable passes through this tube and if corroded it cannot slide easy, likewise if the unit is damaged it will also continue having the problem.

Customer: replied 2 years ago.

thanks Joe.

Did you watch the youtube video?. Does this action look normal to you?

It seems to me that even with air, the piston in the cylinder is quite well sealed.

I recently found out that the grooves for the spanner need to be facing up and down for the control valve to work correctly. Is this true?


Expert:  Joe replied 2 years ago.
Good afternoon Dave,

The piston would appear normal as they normally do, the portion you would want to concentrate on is that tube you put your thumb on that the cable passes through, generally it is scored or corroded and or will no longer provide proper movement and thus why it is hard to steer. That tube should easily slide fully in both directions and also not be damaged inside of it. In terms of a spanner, etc, I have never actually taken an actuator apart, I have either had to clean and lube them or replace them so I would be unsure about any grooves facing up/down, I would assume this would line something up to function correctly, I am honestly not sure, but I can say that the piston is moving fine and I have a feeling you'll find the problem being with the tube. I will try to locate info on the spanner grooves.

Customer: replied 2 years ago.

by tube do you mean control valve?

Expert:  Joe replied 2 years ago.
Good morning Dave,

I was referring to the tube the cable passes through, the cable should move freely inside of it back and fourth. Where you are at is you have swapped in a known good pump and no fluid/hose problems, have isolated the drive and cable/helm and they all function correctly, this only leaves the actuator as the source of the problem and thus why I stated I would first check for corrosion or damage to that tube but can also be the end of the cable that slides through the tube requiring cable replacement. You need to completely remove the cable from the actuator tube and inspect both the tube and the cable, it should easily move in and out of the tube. In terms of those 2 grooves a wrench would fit on, I am not sure they actually matter as I seem to locate them in many directions (many up/down) but also in other direction without issue, my assumption is that they are there for a wrench to hold it in place for removal.

Check your cable and tube for black, rusty, sticky grease and or metal shavings and wear, in some cases you can simply clean all the old grease off of the cable and inside the tube both required, and then re-lube and have everything working again.


Related Boat Questions