Wagner 700 helm system

philmitch · Jul 19, 2024

Hi all,
Proud owner of a 41' president trawler here with a question about the helm function. Both the upper and lower helm act the exact same way in that they are relatively easy to turn and the rudders respond correctly. Helm pumps are 700 Wagners.
The thing is, both helms become noticibly harder to turn when the rudder is all the way over but they will both turn indefeinately.

Recently had an old school marine tech look at it and he said it is normal.

Can someone please enlighten me if this is as designed as it doesn't seem right to me.
Thanks very much,
Phil

Turtle Blues · Jul 19, 2024

Assuming this is a hydraulic system, you are pushing against the relief valve. Rudder arm can't go any further, fluid has to go somewhere. Also doing repeatedly is a good way to blow a seal.

C lectric · Jul 19, 2024

I have a Wagner system. I am guessing but my guessing says you have leaking piston cup seals in the cylinder that actuates the rudder. As seals wear they can allow oil to bypass the piston.

Untill you hit that point the rudder will still turn and do so easily. But once the piston has run out of travel the turning will become much stiffer without the cylinder and rudder going anywhere. That stiffer is the oil bypassing the piston seals.

Reseal the rudder cylinder. If you are not comfortable doing that then contact a hydraulics shop. If like mine it has two small square O rings at each end and two cup seals on the piston along with two O rings on the piston.

They should be readily available from and decent hydraulics shop.

For old time mechanics his opinion is not wrong , at least to me, but not to be ignored either. He has likely seen many boats with similar wear signs and they may work for a bunch of time yet. But for me it is time to reseal.

philmitch · Jul 20, 2024

C lectric said:
I have a Wagner system. I am guessing but my guessing says you have leaking piston cup seals in the cylinder that actuates the rudder. As seals wear they can allow oil to bypass the piston.

Untill you hit that point the rudder will still turn and do so easily. But once the piston has run out of travel the turning will become much stiffer without the cylinder and rudder going anywhere. That stiffer is the oil bypassing the piston seals.

Reseal the rudder cylinder. If you are not comfortable doing that then contact a hydraulics shop. If like mine it has two small square O rings at each end and two cup seals on the piston along with two O rings on the piston.

They should be readily available from and decent hydraulics shop.

For old time mechanics his opinion is not wrong , at least to me, but not to be ignored either. He has likely seen many boats with similar wear signs and they may work for a bunch of time yet. But for me it is time to reseal.

Thanks for the detailed answer. Very much appreciated!

philmitch · Aug 23, 2024

Wanted to write exactly what the outcome of this was in case someone goes down the same path. I removed both helm pumps and the rudder cylinder.
When the cylinder was dissasembled, the seals literally fell out in pieces. The helm pump seals were intact but hard as a rock.
@C lectric - You were spot on in your suggestion above and again, thank you.

Now, rebuilt and bled correctly, there is a hard stop both ways when the rudders are hard over.
The mystery is solved.

Wagner 700 helm system

philmitch

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Turtle Blues

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C lectric

Guru

philmitch

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philmitch

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