Steering fluid leak in autopilot

[MichaelB1969]

Well, this trip from San Francisco to Monterey seems to have been a good shake down cruise. So far, just a few minor issues. Just found a minor leak in the autopilot. Plan is to keep autopilot on and just keep an eye on it. Sound like a reasonable plan? See photo after about an hour running.

 

[GregBrannon]

What's leaking? Do you have a fluid reservoir where you can monitor fluid level and pressure? If so, check that and keep the system healthy. Small leaks sometimes grow, depending on the source. Is the autopilot system somehow separate from the helm(s)? My helms and autopilot share fluid and ultimately control the single remote steering cylinder at the rudders, so a leak in either is a leak to all.

 

[MichaelB1969]

I believe they are separate but I'll do some checking now. Thanks.

 

[MichaelB1969]

Seem to be separate. The base steering system schematic shows hydraulic lines that run between the upper and lower helm and steering piston. No autopilot in the mix. Here's a photo of the piston and you can see 4 hydraulic lines. One set for the autopilot and one for manual steering. On the autopilot pump, the two hoses from the piston are connected, but there is a third hose that I'm not sure about.

Also, while I'm pretty certain they are separate systems, not sure if fluid from the manual steering side can leak back out of the piston through the autopilot pump? Getting well beyond my current experience level. Trying to learn though.

Gonna find the autopilot manual to see what I can find out.

Here's a photo of the autopilot pump and the steering piston.

 

[GregBrannon]

In the second picture it looks like the helm inputs/outputs and autopilot inputs/outputs to the remote cylinder all come together at ganged or cascaded connections at each end of the cylinder. It's hard to tell from the picture's perspective, but I'm not sure how it would work otherwise since both the auto and manual systems control the same remote cylinder

 

[MichaelB1969]

The two that I assume come from the helm are not connected to, or cascaded from the autopilot hoses. They just run separately. I assume that the two hoses on either end of the steering piston are one from helm and one from autopilot on either end?

 

[Xsbank]

With that system, the source has to be from a joint. Get your wrenches out and tighten all that you can see. Of course, the visible oil is running downhill along that bundle from the actual leak. Also, you will have the fun of wiping up ATF for weeks to come, even after fixing the leak. It likes to hide and reappear when your clothes are clean. Ask me how I know...?

 

[GregBrannon]

I probably confused your vision of the system by calling one end of the remote cylinder an 'input' and the other an 'output,' as though one was always an input and the other the output. Either end can be an input and the other the output at any time. The fluid moves in both directions. With that in mind, perhaps you can see what I mean by the systems being combined where all of those hoses are connected at each end of the cylinder. Visualize the fluid taking the path of least resistance as it comes out either end of the cylinder. If there's a leak in the autopilot hoses (or anywhere in that path) the pressure will be slightly less along that branch, and the fluid will favor that path, slightly for small leaks, more for large ones. Checking the system fluid level and pressure will be your best indication of the health of the system.

Or my vision of your system is completely wrong, and yours is the more correct. I can certainly accept that since you're much closer to it.

 

[MichaelB1969]

With that system, the source has to be from a joint. Get your wrenches out and tighten all that you can see. Of course, the visible oil is running downhill along that bundle from the actual leak. Also, you will have the fun of wiping up ATF for weeks to come, even after fixing the leak. It likes to hide and reappear when your clothes are clean. Ask me how I know...?

I think I found the leak. You are right, seems to be from the joint. The leaky joint is uphill of the leak as you suspected.

I don't have a large wrench to put much leverage on it so couldn't budge it...and quite frankly it seems to have pretty much stopped on its own, so don't want to make matters worse by pushing my luck while underway with 3 hours to go.

Thanks for the tip!

Mike

 

[Xsbank]

Wrap the area with a shop towel or an oil pad so it doesn't make a bigger mess.

 

[MichaelB1969]

Wrap the area with a shop towel or an oil pad so it doesn't make a bigger mess.

Got clean paper towels under it!

Will be interesting to see if they are still white in an hour.

 

[C lectric]

Keep a CLOSe eye on the fluid levels.
The A/P and the manual steering are NOT separate. They join at the cylinder.
A leak in one will eventually affect the other.

If you have the oil absorbent pads they are even better than paper towels. I will say though that the Scot Blue shop paper towels are a far cry better than the white towels.

 

[MichaelB1969]

Keep a CLOSe eye on the fluid levels.
The A/P and the manual steering are NOT separate. They join at the cylinder.
A leak in one will eventually affect the other.

If you have the oil absorbent pads they are even better than paper towels. I will say though that the Scot Blue shop paper towels are a far cry better than the white towels.

Thanks for the guidance. I think you are right. I found the manual and the manual helms join up with the autopilot so it's one closed system. I've been keeping an eye on it. Fortunately it's a very slow leak and I'm about to pass under the Golden Gate Bridge. So almost home.