Power Steering Issues

[toesford]

New to Forum: I purchased a 1989 2557 Montego two years ago. I have been "slowly" refurbishing her. She has a 5.7 litre Mercruiser with Alpha stern drive. Has a total of 496 hours since new. Started her up when first purchased with mouse ears and she ran fine. This weekend, fired her up again on mouse ears and found power steering not working. Two things. I did not notice if working two years ago. This past weekend I found she was empty of power steering fluid so topped it up. Found it was leaking from a loose fitting under engine into bilge. Tightened clamp and solved that problem. Soooo - what could be causing my power steering not to work? Possibly air in system? If so, how do I bleed it? Just replaced trim limiter and sender units. Never want to do that again. Stupid engineering for through hull fitting but that is another story.
I have other issues I will be asking for help with. Thanks all. One other thing. A marine mechanic told me the boat is underpowered with the 260 hp and will have trouble planning etc. Is this so?

[Viper]

Short of an actual pump or steering cylinder failure, trapped air is usually the cause of several symptoms, especially after a leak. Some other causes for no assist from the pump are sticking by-pass valve, contaminated oil, failed components from running dry (after fluid loss), etc. Turning the wheel back and forth several times will usually get rid of the air or you can crack open a fitting at the cylinder while someone turns the wheel. Does the pump make a whining noise during operation?

Feel around your steering cylinder for oil, it may be leaking. The other possibilities are a bad steering cable or helm. To eliminate those, disconnect the cable at cylinder and operate the helm, it should turn with very little effort. Also insure nothing is physically interfering with the steering behind the engine.

If you think replacing the trim limit and sender assembly on a Merc is bad, you should try doing it on a newer Volvo

[toesford]

Thanks Viper. Lots of options to look at. Like the idea of first disconnecting cable to see if free. I have had lots of those go bad over my years but only on runabouts. This is much bigger. Pump sounds fine. Hopefully just air trapped and I can work it out.
Still waiting for a reply about power of this unit for this 5500 lb empty boat. Fully loaded should top out at about 7500 I believe. Just two of us. You know the story, 6 for cocktails, 4 for dinner, sleeps 2.

[Viper]

Would be better with a 7.4L for sure. Maybe someone with the same package as yours will chime in with their numbers. Have you tried getting her on plane yet, and are you using drive trim and the trim tabs properly? What is your achieved wide open throttle rpm?

[km1125]

I had a 25.5' boat with a 215 hp inboard and didn't have any issues. Would cruise in the low 30's and top out in the high 30's.

With 260 HP, if you have trouble planing I'd think all you'd need to do is some prop adjustments, even if that loses a few MPH at the high end.

[Cooler]

I would not rate it as under powered, unless your expectations are to go 45 mph. Also, your WOT is probably closer to 4400 RPM, if the boat is propped right. er

[toesford]

Thank you all for your suggestions. It was my marine mechanic that suggested she was under powered. I haven't put her in the water yet. That will be next spring. Fired her up this morning for winterizing. One smooth running machine. No issues other than the temp sensor which I will change. I have run lots of hot outboards back in my day. Use to build 3 point hydros. This is new to me. Well experienced in trim etc and props. Will wait and see. May just need a 4 blade to put her up and cruise. This is a beach cruiser not a cigarette go getter. I'll be happy if she sits around 25 mph at 3000 rpm without strain. Next spring all. Will let you know. Now just waiting for my new head and sanitation hoses. She smells.

[tomschauer]

Hello, and hope it works well for you. I also don't believe it will be under powered. May be a little slow getting on top of the water when fully loaded but should be fine otherwise.
If you haven't done so yet, before you try to splash it, split the lower unit and replace the water pump impeller and housing. This should be done every couple of years of regular use. If your temp sensor says it was overheating, it was most likely correct and will be corrected with a new raw water pump.