2003 5.7 mercruiser- locked up steering

[jh49tpro]

Hey Everyone,

My family and I own a 2003 24/7 hurricane deck boat with a 5.7 mercruiser inboard/outboard. Recently the boat overheated and we had to replace a bad impeller. Our local marina fixed this problem and on my first day back using the boat the power steering completely locked up.

I exited my slip, drove to my location with no issues and was maneuvering to drop the anchor when the steering wheel completely locked up. I couldn't budge it one way or the other. I opened up the back hatch and noticed power steering fluid leaking from the reservoir into the bottom of the hull. I turned the motor off and was able to move the steering wheel/outdrive at will with the motor off. I restarted the motor it was fine until I turned the wheel all the way to the left/right, it again locked up once it was either all the way right and left. It seems to happen only when the wheel is all the way left or all the way right. In order to get back to my marina i had to take it slow and make sure I didn't turn the wheel to far either way (it of course locked up when trying to put the boat back in the slip).

My marina thinks it could be the steering master cylinder but they said they have never run into this before. When the impeller went last week the engine got extremely hot, could this have something to do with it? Anyone have any suggestions or had this happen to them?

Any help would be greatly appreciated! Thank you.

J

 

[guyjg]

The fluid goes thru a water heat exchanger...could have gotten hot and cooked the reservior seals. The pump/reservior assy. will be cheaper at an autoparts store.

 

[Chippacket]

Hey mate, did you ever work out what the problem was? I had exactly the same problem on a 2003 4.3 V6, Alpha 1, gen 2+. I bought the engine and drive second hand but in good condition. After the extensive and expensive engine swap I took it out for the first test run. Backing away from the landing I turned to full lock right to point the boat up stream but quickly discovered it had locked up solid. The only way to release it was to turn the engine off. Now it allowed the pressure to release and centralize the steering again. I restarted and discovered I had no problem with the steering in either direction unless I turned to full lock in either direction. Hence the boat didn't go any further that day for it's first test run other than back on the trailer.

For the moment I have removed the pump and lines completely. I still have the actuator on there but have removed all the seals and "O" rings from inside so the actuator can never build a pressure.

I'm keen to refit the power steering but don't really know if it's an error with the pump or the actuator. This is an interesting subject you've bought up because all my local Merc dealers said they've never really come across this issue. Your's is a V8 and mine a V6, but it's interesting they are both 2003.

I don't want to waste the money on a new actuator and discover it's a problem with the pump or elsewhere or change the pump and discover it's a problem with the actuator.

I believe it's a problem with the actuator. With the engine "Turn off", and watching the actuator, it would ever so marginally "catch" at full lock and showed a marginal delay in returning equal to steering inputs. Therefore when running I'm guessing it would have a moment where it's trying to send the fluid pressure in opposite directions at the same time resulting in hydraulic lock.

Seems there's limited answers for this one from either Merc dealers or forum sites.

Would love to know what you discovered as the problem part that malfunctions.

Cheers.