Helm pump, pumping air?

[JRC]

Hi

We have a Puget Sound 34, newly purchased, and we are having problems with the hydraulic steering. Its a three pipe rig with a Seastar ram and lower helm and a rather older (unmarked - see photos) upper helm - possibly the original. I set up a bubble purge system and started pumping the upper helm in a clockwise direction - three fast turns and then a pause to let the bubbles out and the oil drain in. This was very rewarding to start with. Lots of bubbles appearing immediately when I stopped turning. Although, strangely, the amount of oil in the suspended bottle only went down a very small amount. Fast forward to around three hours later, exhausted by now, and still doing the same and still the same amount of bubbles appearing every time. That's around a good litre of air (a quart) out at a rough guess, but at most, only .2 litre of oil that went in. There are no leaks in the system.The only thing I can think of is that the helm pump is sucking air in from somewhere? Has anyone else had this experience? Or should I just keep pumping? If anything now, the steering is worse than when I started.
The only strange thing I can find in the set up is that the check valve (three pipes on one side and two on the other) is set up the opposite way to that shown on the Seastar web site (diagram attached). The three pipes are on the helm pump side of the valve, rather than on the ram side. Although this doesn't look like it has been disturbed for a long time (see attached photo), so it was probably originally installed that way. Does this matter?
Any help or advice would be most gratefully received!

 

[Iggy]

I never had that problem with my boat. But I am a ferry Capt. and that boat had the same problem. The mechanic said to leave the fill cap off over night on the flybridge. The air will slowly come up.

I don't know if that truly works but it can't hurt. If you have that much air in the system you might have a leak.

 

[mvweebles]

For some reason, the check valve was installed upside down. The third tube to helm pump is a return. Without it, there's no place for the air to go. The port is clearly visible on back of helm pump. Why oil isn't leaking out is a mystery- maybe a knockout needs to be removed? A call to seastar may be in order.

BTW - brass tees appear to be fairly new. The plastic tubing is fairly new too. Steering has had work. I cannot imagine why the check valve was not installed correctly. Maybe there's a reason?

Peter
View attachment 137623

 

[JRC]

"Far from an expert here. I dont have a ton of experience - have never seen a system with outside check valve (they are neormally integral to the helm pumps)
Some thoughts that may help, perhaps spur some comments by others:

Keep in mind, the helm pump serves two purposes. First, it is a manual hydraulic pump of course that operates at up to 900psi. But second, it is a small reservoir at the high point of the system.

First, brass tee fittings near ram look much newer than the surroundings. Steering has had work on it?

Second, how do you fill the system? Should be a port on top of helm pump. Without the return line, not sure how the fluid would be recirculated.

Third, although not shown in the Seastar schematic, I believe there is normally a crossover valve at the ram. This allows the fluid to make circular trip without moving rudder and evacuate air.

Fourth, the third line to the helm pump is a return. This is where the air would be evacuated. The port is clearly shown on the back of your helm pump, 12-o'clock position.

I cannot understand why the check valve was installed upside down. But I have no idea how you'd get the air out of the system if this tube doesn't go to the reservoir - the high point of thr system.

Frankly, while easy to say the check valve should be reversed, I'm guessing there's a reason it was installed the way it was, but i cannot figure out how the air would be evacuated without the return line to a highpoint. A call to Seastar is in order. You may want to do a sketch of your schematic.

Good luck. Please update when you know more."

Hi Peter

Thank you for your considered thoughts.

First. Yes, the steering certainly has had work done on it, but the previous owner is totally non-communicative, so I don't know what, or how well, it was done. Also some other work on the boat is, shall we say, a little unfinished?

Second. There is a small reservoir connected to a port on the top of the upper helm pump. For purging purposes, I replaced this with a plastic bottle and a clear tube so I could see any (lots!!) bubbles.

Third. I have fitted a crossover pipe to the ram to allow circular fluid movement - its the clear pipe in the photo with brass fittings.

Fourth. The return pipe goes to the 7 o'clock position on the pump as it is at the moment.

Fifth. The schematic I posted was Raymarine, not Seastar - my mistake - I've looked up so many sites it gets a little confusing! It's that which shows the outside check valve, which seems to be a vital part of three pipe hydraulics when fitted with an autopilot pump.

I'm tempted to bite the bullet and fit a new top helm pump, check valve and autopilot motor and have already emailed Seastar for their advice - waiting to hear. I'll let you know what transpires.

 

[mvweebles]

Most helm pumps have check valves integral to them. They can get a bit expensive but the biggest challenge will be retrofitting.

Peter

 

[Comodave]

Try contacting boatsteer.com. They rebuild SeaStar helms and cylinders. They are significantly cheaper than buying a new one and I believe their warranty is the same as new.

 

[Antares]

I just bled my helm yesterday after replacing a section of damaged tubing. My steering system has upper and lower Capilano 250v helm pumps and an external Univalve check valve. Your check valve is inverted compared to what I have. My return line is on top. The two port side goes to the cylinder with the two autopilot pressure lines teed in to those two times. The autopilot pump return line tees into the return line on top of the check valve.
I'll try to post the diagram of my set up.

 

[Antares]

Here is the Capilano ststem

 

[Antares]

Here is the Capilano ststem

 

[Jay N]

For WESTERLY when purchased in 1997, there was evidence of steering fluid overfill at the helm pump when the system was warm. First solution was to stop off the helm pump resevoir, and install a larger/remote reservoir tank.


This worked fine, but didn't solve the large volume differential between cold and warm operations. About a year later, I was able to determine that the steering ram had been installed upside down, so that any air in the system was unable to bleed off.


After installing the ram properly, the steering system has been very reliable, the remote tank not needed.

 

[JRC]

Here is the Capilano ststem

Thank you for that. The system shown there is exactly what I have. Which gives me more confidence.

 

[Antares]

Here is the complete pdf for installing and bleeding Capilano steering systems.

 

[Keysdisease]

Both the Seastar and Capilano steering are vented systems. The fill on the lower helm is a non-vented plug and the fill on the upper helm is a vented plug. As mentioned the "check valve" is the long discontinued "uniflow" valve.

$00.02

 

[JRC]

Both the Seastar and Capilano steering are vented systems. The fill on the lower helm is a non-vented plug and the fill on the upper helm is a vented plug. As mentioned the "check valve" is the long discontinued "uniflow" valve.

$00.02

Thank you. My overall conclusion is that there is an air leak by the old upper helm , plus air in the system somewhere and probably quite a lot. But what is happening when I turn the wheel is that air is TEMPORARILY being pulled into the reservoir and as soon as I stop turning, it is then ejected again. So basically, I pull an air bubble in under vacuum using the pump and then, with the other air in the system acting as a damper or spring, the newly introduced air is promptly pushed back out again as soon as the pump is stopped.

The decision I've come to is to replace the vintage helm pump with a new Seastar unit and to replace the autopilot pump with a new Raymarine unit.

Specifically regarding the "Check/Uniflow Valve" and it being long discontinued... Does this now mean that I can simply remove it from the system altogether?

 

[mvweebles]

Specifically regarding the "Check/Uniflow Valve" and it being long discontinued... Does this now mean that I can simply remove it from the system altogether?

Probably - confirm with Seastar that the helm pump has integral check valves (almost certainly does).

Please update with whatever you find -

Peter

 

[JRC]

Reply from Seastar... Yes you 100% remove the existing uniflow

 

[Brooksie]

I have similar helm pumps. Your pictures aren't too clear but in addition to the two pressure lines, going to the cylinder; the two helms need a line between them for air to proceed from the lower helm to the upper helm then vent out. The lower helm can't really have a vent b/c the upper helm would spill its fluid out of it. So, look at the instructions and run a line between the top of the lower helm to the upper helm so both can vent out of the upper helm vent.

 

[Patrick4002]

seastar pump problem

my upper pump had air in it the pumps where leaking on the shaft seal and on the tilt screw (we can adrust the pump output)

to revice these pumps is very simple you can find most info here on the trawler forum with the search for seastar repair.

i had to replace 2 o-rings you can find them as revision pack or order them online they cost a few euro/dollar for a pack of 10 the work was about 1 hour to disassemble and assemble the pump back, no problems anny more is only a messy job

 

[mark ketcham]

Cylinder orientation traps air

Found mine had been installed with the Ports on the bottom side, I see yours look like they are on the sides, can you rotate them to the top?