Hydraulic Steering
Hydraulic Steering
Under the "what are you working on" topic in this Technical Forum, Jay mentioned that he is looking at a new Hydraulic Steering system using Teleflex Sea Star hardware. I accomplished this a few years ago on Catherine Ann, so thought I would gather what I had learned into a new Technical Section article titled "Hydraulic Steering". Catherine Ann had cable steering originally, so this turned into a slightly more complex project than replacing a previous hydraulic system. One of the things that I learned is that other than the key Sea Star helm pumps and actuating cylinder, the rest of the system components can be obtained without the "marine" price tag. It could even be argued that the actuating cylinder does not have to be a "marine" unit.
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WaterCottage
- Posts: 88
- Joined: Wed Jul 18, 2007 7:08 pm
- Location: Nanaimo, B.C.
Re: Hydraulic Steering
Wow, interesting. Thanks for the info.
I know that the two pump reservoirs have to be joined, with the bottom one capped, and the top one vented, but this generally implies a flying bridge where the bottom hose connection can be brought straight up to the top. This allows any air bubbles to work there way up to the top reservoir. In my case the second helm is deck level at the back, and therefore the hose connection would have to go down from the the lower front helm(alongside the two steering hoses) and back up. This would allow air to be trapped. I think that if I vent both to atmosphere, but have a hose from the lower front that just goes up alongside the window frame, with it's top at the same level as the rear helm, I should be OK. I would just have to keep an eye on fluid level in two pumps, rather than one.
The big question is how did you bleed the system? Do you just keep the reservoirs filled and crank the wheel with the bleeder open on the steering ram with a hose going into a bucket? Does this do a good enough job?
I found this video on Youtube, but these powerbleeders have the usual "Teleflex" price. $600 or so, I think.
As a side note, I noticed that Teleflex stamps the size rating for the pumps on the tip of the shaft where the steering wheel goes. 1.7, 2.0, or 2.4 Handy to be able to tell if a pump is bought without documents.etc.
http://ca.youtube.com/watch?v=nEZlfRfCDzA
Jay
I know that the two pump reservoirs have to be joined, with the bottom one capped, and the top one vented, but this generally implies a flying bridge where the bottom hose connection can be brought straight up to the top. This allows any air bubbles to work there way up to the top reservoir. In my case the second helm is deck level at the back, and therefore the hose connection would have to go down from the the lower front helm(alongside the two steering hoses) and back up. This would allow air to be trapped. I think that if I vent both to atmosphere, but have a hose from the lower front that just goes up alongside the window frame, with it's top at the same level as the rear helm, I should be OK. I would just have to keep an eye on fluid level in two pumps, rather than one.
The big question is how did you bleed the system? Do you just keep the reservoirs filled and crank the wheel with the bleeder open on the steering ram with a hose going into a bucket? Does this do a good enough job?
I found this video on Youtube, but these powerbleeders have the usual "Teleflex" price. $600 or so, I think.
As a side note, I noticed that Teleflex stamps the size rating for the pumps on the tip of the shaft where the steering wheel goes. 1.7, 2.0, or 2.4 Handy to be able to tell if a pump is bought without documents.etc.
http://ca.youtube.com/watch?v=nEZlfRfCDzA
Jay
Re: Hydraulic Steering
Hi Jay,
An interesting situation with two helms that are not one above the other. You are right that the vent path cannot have any low spots or air will be trapped. I would agree with your plan to vent both helms to atmosphere with a hose extension on the lower one to bring it's vent height up to the same level as the higher one.
Bleeding the system is quite straight forward and the Sea Star installation manual has a good description of this. First you do one helm and the cylinder completely, then you do the other helm. I think this will work equally well for your setup. This info is likely available on the Teleflex website. If not, I will scan from my manual and add to the tech article.
One person can bleed the system by keeping the fill container (connected to the vent plug location during filling) topped up and keeping the hose from the cylinder bleed screw(s) submerged during the entire fill operation. Use a clear hose and a clear container at the cylinder end, so you can see exactly when there are no more bubbles coming through.
Good tip on the pump size ID stamp.
Rob
An interesting situation with two helms that are not one above the other. You are right that the vent path cannot have any low spots or air will be trapped. I would agree with your plan to vent both helms to atmosphere with a hose extension on the lower one to bring it's vent height up to the same level as the higher one.
Bleeding the system is quite straight forward and the Sea Star installation manual has a good description of this. First you do one helm and the cylinder completely, then you do the other helm. I think this will work equally well for your setup. This info is likely available on the Teleflex website. If not, I will scan from my manual and add to the tech article.
One person can bleed the system by keeping the fill container (connected to the vent plug location during filling) topped up and keeping the hose from the cylinder bleed screw(s) submerged during the entire fill operation. Use a clear hose and a clear container at the cylinder end, so you can see exactly when there are no more bubbles coming through.
Good tip on the pump size ID stamp.
Rob
Re: Hydraulic Steering
Filling and purging the system . . . .
Even though the following Sea Star information
http://ww2.seastarsteering.com/OUTBOARD ... urge.htm&1
starts our with
"These instructions show how to fill and purge a Single Station, Single Cylinder System" and
"This procedure requires two people"
If you page down, you can find the procedure for Two Stations . . . . and I did not have any trouble
doing this with one person, as described earlier.
Rob
Even though the following Sea Star information
http://ww2.seastarsteering.com/OUTBOARD ... urge.htm&1
starts our with
"These instructions show how to fill and purge a Single Station, Single Cylinder System" and
"This procedure requires two people"
If you page down, you can find the procedure for Two Stations . . . . and I did not have any trouble
doing this with one person, as described earlier.
Rob