Autopilot and SeaStar question(s)

[kirk a]

I have a Simrad AP 22 installed on my 2003 330, and assume it is original equipment. The helm is a sea star. What I’ve noticed is that the autopilot will wander a bit, leaving an S shaped wake. It seems to be worse in chop than on flat calm conditions, but it happens then too.

I’ve also noticed that when manually steering, every once in a while there is some “slip” or “jump” where the wheel turns easy. The seastar system has been bled a couple times since I acquired the boat in 2019. I have no reason not to believe this is also original.

Fall is rapidly approaching and I’m starting to think about the winter punch list items. Thinking about having the sea star helm removed and sent out for a rebuild, assuming that the interior seals are likely the culprit of the steering slip and even if not, the system is 20+ years old, and it is a good idea from a preventative maintenance perspective.

On a canyon trip last week, I sort of put these two things together in my head, and wonder how likely is it that the autopilot wandering may be related to the steering slip I experience? I’ll note that I have zero experience on new boats, so I’m not sure if that slip/jump is normal or not. Also don’t have experience with other autopilots, and wonder if my expectations are high, or if a new autopilot would correct that wander, even if the helm was not rebuilt.

 

[deepwaterdreamer111]

I would start with bleeding the air out of the steering system. If you have a mechanic have him do it with the seastar purge kit.

 

[seasick]

If you say you have already bleed the system and did it correctly)) I would then disable the autopilot and see if the skipping (slipping) still occurs. You can also try turning the wheel with the boat at the dock to see if it slips. The slipping can be an air pocket or leaky dirty check valves. The later can be due to old contaminated fluid.
I suspect that the slipping occurs more in choppy seas because there is more strain on the steering especially as the auto pilot tries to course correct.
The problem could also be totally auto pilot issues, perhaps the gyro compass. First thing is to determine if the issue occurs when auto pilot is off. If so, I would try the flush with new fluid and them refill and bleed ( read the bleeding instructions. ) It is hard to bleed correctly by yourself and without one of those bleeding kits.

 

[Halfhitch]

I had the experience of the steering not reacting properly on my boat when driving straight ahead. I would turn the wheel as normal, and the engine would not move till I quickly moved the wheel. It turned out that the barrel of the SeaStar steering cylinder had corroded internally right where the piston sat when the engine was centered. That pitting of the cylinder let fluid pass by the piston without moving the engine when steering gently and would move the engine when speeding up the rotation of the steering wheel. I took the cylinder down to Boat Steering Solutions here in Venice, Florida and they gave me a decent trade-in value for my old one. They have a website. Friendly people.

 

[SkunkBoat]

I had the experience of the steering not reacting properly on my boat when driving straight ahead. I would turn the wheel as normal, and the engine would not move till I quickly moved the wheel. It turned out that the barrel of the SeaStar steering cylinder had corroded internally right where the piston sat when the engine was centered. That pitting of the cylinder let fluid pass by the piston without moving the engine when steering gently and would move the engine when speeding up the rotation of the steering wheel. I took the cylinder down to Boat Steering Solutions here in Venice, Florida and they gave me a decent trade-in value for my old one. They have a website. Friendly people.

I had exact same thing. And it effected the AP also. Replaced the cylinder. fixed


Another symptom is that the raised motors will "fall over" to one side overnight.

 

[Sardinia306Canyon]

have a Simrad AP 22 installed on my 2003 330, and assume it is original equipment. The helm is a sea star. What I’ve noticed is that the autopilot will wander a bit, leaving an S shaped wake. It seems to be worse in chop than on flat calm conditions, but it happens then too.

I had this on my Reactor 40 and Seastar cylinders, but it was a setting on the Reactor setup.
I will try to find my tread in THT as i remember that i wrote the fix there, then you must find the same but with probably other name setting for your Simrad AP.

Here we go:

I had initially a problem with snaking (oversteering) only when following a route while heading hold worked perfectly.
The snaking problem was the setting: Steering Mode Setup --> Steering Mode --> "Step", where "Step" was was the wrong setting.
I changed the above setting to "Rudder" and AP is working perfect in either way, route or heading hold.

I’ve also noticed that when manually steering, every once in a while there is some “slip” or “jump” where the wheel turns easy. The seastar system has been bled a couple times since I acquired the boat in 2019. I have no reason not to believe this is also original.

The jump or jerk movement is a typical sign of low oil in the helm pump, not by air in the lines.
I had this many times on man boats, but without hydraulic pump, just normal Seastar helm pump and it was a sign that i had to fill oil.
Check your oil level, but verify first how to do it on your system.

Honestly i would not spend money for a overhaul of a 20 year+ helm pump and bite the bullet to buy a new one even if they are around 800$
Maybe you find a company who accept a trade-in and apply a reasonable discount.

Chris

 

[loubeer]

I have the same AP22 on my 2003 330 Express. It was installed by the original owner of the boat. It's been a solid unit and I have had no issues. However, as Kirk has said, if I did have issues, I would not put major money into the repair. A new unit will be engineered better and probably perform better. Be happy that the AP22 lasted as long as it did .

 

[kirk a]

This is quite helpful. I think that I'll add a new helm to the winter list and take my chances with that improving the AP performance next year, and if not, well then I add a new AP at that point.

@loubeer - is your AP networked to your plotter? I believe it can be done with NMEA 0183. but mine is standalone.

 

[SkunkBoat]

The new helms have different threads and use ORB fittings. An improvement that makes tightening and angling the fitting easier. But it means you need new fittings.

The Tilt helm isn't sold without the tilt mechanism. You can't use a non-tilt new helm pump with your old tilt mechanism. The shaft of a tilt pump is different.

 

[Sardinia306Canyon]

Well, if hydraulic hoses are same year as helm pump then i would change them in any case.
If actual hoses are rather new, then Dometic/Seastar has a adapter from ORB pump to NPT trad of older helms, part number is HF6012
Original seastar hoses are not cheap but they last a long time and a far offshore breaking one can put boater in deep troubles.
It is my experience that troubles on a boat happen in most cases when conditons are shitty.
Chris

 

[loubeer]

This is quite helpful. I think that I'll add a new helm to the winter list and take my chances with that improving the AP performance next year, and if not, well then I add a new AP at that point.

@loubeer - is your AP networked to your plotter? I believe it can be done with NMEA 0183. but mine is standalone.

Yes - Simrad EVO3