help with autopilot / steering problem

Does anybody have any thoughts on the following problem?

My system is a Robertson autopilot with reversing pump steering control connected to Capilano 3 line steering helms. (Mine utilizes the return line to the uniflow valve)

Forgive my long winded explanation, I've tried to include all relevant info in the event it may help with a diagnosis. The problem is: If I turn the rudder to starboard or port using the autopilot pump controls, then immediately try to return the rudder to center by turning the "wheel" in the opposite direction it takes 2 or 3 complete turns of the wheel for the rudders to start moving. However, if I turn the wheel in the same direction as the pump was turning it, the rudders respond to the wheel normally.

OBSERVATIONS
- If I let it sit for a minute without touching the wheel or pilot controls, the rudder responds to the wheel normally in both directions.

- If I let it sit for a couple of days, the wheel turns with no resistance and must be turned back & forth a couple of times before it starts engaging the rudders. Same thing with the autopilot pump, it runs for a good minute before the rudders start moving. After that it behaves as above.

-When I bleed the system & top up the reservoir at the upper helm, when I come back to it after awhile & turn the wheel, oil floods out the plug/ air bleed on top of the reservoir as if it was overfilled. (Don't think overfilling is possible, it is either full or not I would guess)

Any thoughts or suggestions greatly appreciated.

Sounds like air in the lines somewhere between the helms, ap pump and down to the rudder cylinder. Need to do a bleed procedure from helms to cylinder, and how to do that varies with the plumbing you've got.

Thanks Ski, it has been bled over & over. Possibly air could be getting in but there are no fluid leaks. I'm thinking possibly a check valve in pump or the uniflow valve but don't know if this would cause these symptoms.

I'm with Ski on this one. I've had similar issues, though not a severe, and it was air related. The problem is that you can bleed and bleed and bleed, and not actually be successful at getting the air out.

I found the bleed procedure provided by Capilano to be unsuccessful on my boat. Mine has a bypass valve between the two ports on the steering cylinder. Normally it's closed, and you open it to enable manual steering with a tiller. It turns out that if you open it, then crank the wheel continuously for about 20 turns in each direction, and do it for each helm station, it bleeds out perfectly. After screwing around with bleed procedures for hours, I finally stumbled on this simple and highly effective 5 minute procedure. I got to test it again a few months ago when my AP pump needed repair and air got in the system again. 5 minutes and all was bled out.

If you don't have a bypass valve, then you are probably stuck with the old way. And I can't be sure my approach will work on every boat, or even any other boat, but it works great on mine.

t.t I have a 3rd line to each helm and the pump which I believe is a return to the resevoir. At the pump there are three ball valves, all open including the bypass. Is this the valve you are referring to?

How is the level in the Oilbottle?
The air press are ok? 30 -40 PSI ?
I have the same robertson steering and i think its a air Problem.
_____________
Norbert

This is a long shot, but this sounds vaguely like the issue we had with our new Simrad (Robertson successor) AP last summer.

Our problem occurred when we were trolling with the AP engaged; whenever there was a fish strike I went to neutral and sometimes forgot to disengage the AP. After a few minutes we would be on the move again but with no steering whatsoever - the wheel would just spin. Shutting off the AP completely would eventually get things working again. Like I say, only vaguely similar.

The issue was that the AP electronic rudder stops were set beyond the physical stops by about three degrees so the AP would just push against the physical stops until it had a heart attack and then for whatever reason the steering was completely disengaged. It was an easy setting to change once diagnosed.

Capt Kangeroo said:

t.t I have a 3rd line to each helm and the pump which I believe is a return to the resevoir. At the pump there are three ball valves, all open including the bypass. Is this the valve you are referring to?

Click to expand...

My setup is the same, but none of those are the valve I'm talking about. What I'm talking about is a bypass valve so you can steer with a manual tiller arm. Your boat may not have one, but if it does it will be between the two pressure sides of the steering, likely down near the steering ram. On my Grand Banks, it's actually attached right to the ram between the two hydraulic ports. On my Nordhavn its behind the ram between two manifolds where the hand steering and AP pumps all tie in. When the valve is open, fluid just flows from one side to the other without moving the ram. But it's intended purpose is to allow the steering to move where the ram and various check valves would otherwise lock it.

thanks guys, much appreciate your thoughts.

t.t I do have a manual tiller, I'll have a look for that valve, unfortunately I have to take apart the aft bed to get to the ram area.

I think Conrad might be on to something however, since this started I have wondered if the pump is building up so much pressure to move the rudders that it is relieving excess pressure by forcing fluid back into the return lines. This might also explain why the reservoir in the upper helm overflows at times. After I stop turning the wheel, I hear groaning from the rudder area and the rudders keep moving a few degrees. Weird!

I did repack the rudders & snugged up the glands months ago so maybe I got them too tight? It is much stiffer to turn than my old boat but the question is, "how tight is too tight"? I tightened them in enough to stop them from dripping. I can turn the wheel with one finger using moderate force.

Norbert, are you saying you have a pressure guage on your steering system? I do not, but it seems off the cuff to be a great idea. I just may add one.

Capt Kangeroo said:

thanks guys, much appreciate your thoughts.



Norbert, are you saying you have a pressure guage on your steering system? I do not, but it seems off the cuff to be a great idea. I just may add one.

Click to expand...

Yes i have this pressure guage on the top of the Oilzylinder.
This is good for a quickly leak control.

http://www.westmarine.com/hydraulic...eastar-power-steering-oil-reservoir--12785226
_______________
Norbert

Capt Kangeroo said:

since this started I have wondered if the pump is building up so much pressure to move the rudders that it is relieving excess pressure by forcing fluid back into the return lines. This might also explain why the reservoir in the upper helm overflows at times. After I stop turning the wheel, I hear groaning from the rudder area and the rudders keep moving a few degrees. Weird!

Click to expand...

Not weird at all. All the behavior is explainable by air in the system.

I think the other scenario that was described is when the AP is still engaged and you try to steer at the wheel. The wheel will move the rudder, but just as fast as you move the rudder with the wheel, the AP moves it back. It feels like the wheel is free-wheeling. At least that's how mine behaves. As soon as you put the AP in standby, full helm control is restored to the wheel.

If you have a manual tiller then I'd be surprised if you don't have a bypass valve. I think that's your ticket to solving this problem.

Capt Kangeroo said:

I did repack the rudders & snugged up the glands months ago so maybe I got them too tight? It is much stiffer to turn than my old boat but the question is, "how tight is too tight"? I tightened them in enough to stop them from dripping. I can turn the wheel with one finger using moderate force.

Click to expand...

That was my thought; if the rudders are binding that could give a similar response as trying to go past the physical stop. When it occurred on our boat putting the AP back on standby after the fact didn't free it up; it almost seemed like it just needed time to catch its breath before it would cooperate again.

On your Uniflow valve there are bleed valves, on the ends, which ,when opened, allow purging directly from the pressure lines to the centre return line. Open those screws too far and you can damage the O rings which may leak OR allow air in.

ONE TURN IS ENOUGH. Maybe even a half turn just so the oil bypasses the cylinder and pushes any air directly into the return line.

Check that those valves are closed. The O rings are easily, messily, changed. I do not remember what size they are. The O rings may also have aged enough they are too hard to seal properly.

How is the steering cylinder mounted. Are the hoses connected on the cylinder top or underneath. If the connections are below you must remove the cylinder , flip it and then do the air purge or the air WILL NOT come out, not for a long time .

Is the Uniflow valve ABOVE the cylinder and the hoses slope up? If not the air will not purge. The lines must flow UP to the valve.

I drop my cylinder into the bilge and flip it to take care of both problems. I have both an upside down cylinder and the Uniflow on the low side so the hoses do not slope up.

Once the cylinder is properly cleared then the little bleed screws in the Uniflow valve can be opened to purge the main pressure lines to the centre low pressure line.

EDIT: EDIT: I'm not going to rearrange the above but I realized that actually you should do the Uniflow and main line purge first and then the cylinder or risk pushing any mainline air into the cylinder you just purged.

I also found after doing this that there would be a TINY bit of air which a good run on a rough day would take care of. Not stupid rough but just enough that you don;t doze off at the wheel. The rolling and pitching will help the air move to the purge fittings.

Be sure you maintain the oil level as the air is purged. The level will drop and if it drops enough the upper helm pump may take in air if the pump intake is exposed or comes even close to being exposed. Then you get to start all over again.

Years ago I rebuilt, easy job???, the steer cylinder and repaired a bunch of leaks and while at it I flushed the system quite thoroughly with new oil. I used a clean 1 gal. fuel jug into which I poured the new oil. I put a hose barb on the fill port at the upper helm and, after putting in some oil with a funnel to start, I connected the jug by simply dropping the hose end into the oil and just started cranking the wheel, this way and that way, and as I did the new oil was pulled in, plus to boot when an air bubble came out it went into the jug and not all over the deck, the controls and anything and everything it could spray onto.
WHEW.

C Lectric. thanks for the detailed post, it will be a great help to myself & others in the future.

I was aware of the uniflow valve & just recently took it out & rebuilt it in an effort to solve my problem. It did not unfortunately. My system is correctly installed with cyl hoses & uniflow correctly mounted. I have also bled the system several times including completely emptying it and putting in new fluid

I think the greatest clue to what is going wrong with my system is the`fact that when turning the wheel, the upper helm reservoir overflows and if I keep turning it then sucks it all back in. (to prevent the mess, I leave a small hose hooked to the bleed plug with the loose end going into a small dish). Of course, after the system expels a bunch of fluid, air is reintroduced and it is a vicious circle.

Technically this problem should be impossible, the system can not be overfilled. I'm at wits end with this infernal thing!

Were you able to find a bypass valve?

Does the overflow occur when turning either upper or lower helm?

I don't know the guts of the Capilano helm, but in general all modern hyd helms have a "blocking valve" that isolates the ports from the internal pump, so no pressure is at the pump unless you are moving the wheel. Also why wheel does not turn when other wheel or ap is in action.

I think there is also check valves that isolate the reservoir volume from the pumping unit or from the ports, not sure about that.

Bottom line is that if fluid is being expelled from reservoir while turning the wheel, one of the helm internal valves might be stuck.

t.t no I couldn't find one, I'm presuming it may not need one for manual tiller operation due to the uniflow valve. Ski, I think we are on the same wavelength, I'm thinking it must be a check in the uniflow or one of the helms acting up. I'm going to try to isolate if it happens with one helm or both. It is now useless doing anything further until I re-bleed the system due to the fluid loss. I still think Conrad has something too with regards to excessive force/pressure building up. What a headache this all is! Neither the upper or lower helm turns the other but.... after turning either wheel the rudders move by themselves ever so slowly a few degrees in either direction back & forth for a minute. The rudders can not be moved by hand normally but during this condition they can be forced in one direction several degrees. After this movement stops, they can not. The problem is getting worse fast as I play with it, if I let it sit for 10 min it seems to want to expel "ALL" the oil in the system out of the upper helm. In fact I have a gigantic mess to clean up as it overflowed my catch dish. I have the obsolete 275V Telestar/Capilano helms, I'm getting close to saying to hell with it & buying a whole new system. The new 2 line systems do away with the uniflow valve. Does anyone have a manual for the 275V in pdf they could send? I googled but could not find one. I have a brochure on the helms that came with the boat but it is largely useless.

This univalve is new to me. How does it fit into the picture?

Kangaroo

I read all the previous posts and note that you are getting a lot of help. Unfortunately a lot of it is generic and assumes a presurized reservoir or check valves in the helms. Older Capilano systems are not presurized with air and the resevoirs are the helms. There are no helm check valve as the univalve is the shuttle valve that lets the steering piston switch its path back to the helms acting as reservoirs. So now for my advice......do what Clectric is saying. He seems to understand that it is difficult if not impossible to bleed the steering cylinder if the hoses tap int the bottom of the cylinder on each end. Next make sure the lines from the cylinder go up to the uniflow valve or you will never get the air out. Last and this is my own recommendation...be sure that the return on the autopilot pump is upstream of the uniflow valve; I think it must be connected at least 6 feet away to keep the pump from affecting the shuttle valves in the uniflow. Good luck and don't get to discouraged. Oh, and take care of that univalve; they don't make it anymore.

See attached uniflow valve information

capilano instructions

fault tracing

I looked at my autopilot instructions and it was as I remembered. You must pipe the autopilot return into the uniflow return at least 6 feet away from the uniflow valve. I'm not saying this is your problem but it could be.

OB Thanks for all the great info !!!!! I have some reading to do. I was aware that some info/help provided concerned different systems than ours, nonetheless all help is profoundly & sincerely appreciated. It always amazes me how a seemingly unconnected idea or thought proves to be the key piece to solving the puzzle

Incidentally, my cylinder lines are indeed off the top and my univalve is approx 35ft from the autopilot pump connections.

I think some of these more obscure random symptoms I'm experiencing this afternoon are simply a case of the system now being full of air. I'm in the process of getting it back to square one by bleeding & topping up then I'll try some process of elimination to see if I can isolate the culprit. I suppose the AP pump could also be an issue if it is allowing pressure to escape to the return line???

OB, what type of fluid are you using in your system? I've been using tranny fluid. My book called for dextron 2 or 3 but I note on the later helms they say specifically not to use tranny fluid.

Capt K

On the top helm try getting access to the fill port and install a hose barb and a length of hose even if you need a tee or whatever due to poor access. It need only be a 1/4" ID line. Put the other end into a jug of clean oil so it is well covered. You may need to add a hose barb at the oil jug end to ensure it stays submerged. It must stay submerged so the hose cannot suck air , instead some of the oil in the jug. Check the level often.

The fact that your system is burping oil all over tells me you have air. That is typical. The air is working its way to the top helm but unfortunately that also means forcing some oil ahead of it and overtaxing the upper helm storage capacity. Yhe jug will stop the mess as long as it is half filled so there is lots of unused space.

A funnel at this point f the process is useless and will continue to defeat your efforts.

Untill you get past that major burping you will continue to have trouble.

As each bubble is cleared then continued wheel operation will suck in more oil to refill the space just as long as that jug end of hose is submerged but only if submerged.

If one wheel does not affect the other I think the check valves are working. That's what they are present for. To stop the other wheel from moving and also ensure the oil from one wheel goes to the steer cylinder and not bypass it at the other wheel.

I asume the system used to work ok. I've not had the trouble but i will emphasize the point about the return line being lead into the BOTTOM of the lower helm and then out the TOP of the lower helm and then carrying on to the BOTTOM of the upper helm. Unless this is correct, air will be caught in the pump.

You must work both wheels one at a time and constantly back and forth from one wheel to the other.

Take a serious look at the lines and if you see any major dips that can trap air you may have to try straighten the dips or some of them out a bit.

These sytems work well. MIne is 35 years old and other than needing to replace the steer cylinder piston seal , an 'O' ring, and fix a few leaks it has been absolutely reliable.

Lots of edit here I will also say that the Univalve bleed ports should be open while all this cranking is going on so all that air goes into the return line and not into the cylinder.

I just reread one of your posts , # 14, and a dish is not good enough. That hose end needs to be buried under several inches of oil. That's why I used the jug. To keep the hose end buried and leave enough air space above so when one of those bubbles burst out, and they do burst, the spray and over flow was contained. That several inches of oil also ensures that NO AIR can be pulled in as long as you check often and top the jug up as needed. Forget once and you will start trouble all over.

Your problems sound a LOT like mine when I went to refill my system. I didn't think of the fuel jug untill I made one heck a a big mess.

I use Dexron in my system. The manual says ~ 5 wgt Hydraulic oil. They used to recommend the Dexron as a second choice. Wagner was not too far from where my B.I.L. and I live and my B.I.L. had the same system and he asked and was told the following since 5 wgt Hyd. oil is not easy to find so an alternate was a 10Wgt mixed 50/50 with kerosene. I wasn't comfortable with that and since my system was originally Dexron I stayed with Dexron. I do have a jug of 10Wgt hyd. as a back up or I have to do it again. The last time was between 15 and 20 yrs ago.

It will purge but it will take some time.
Good Luck

The bleed process described in the manual is exactly how I did it on my boat. The only difference is the univalve, which is built in to more modern helm pumps. Also, the univalve accomplishes the same function as the bypass valve in my system. Opening the two bleed screws on the univalve allows oil to flow freely from either port to the return.

The issue with bleeding without an opened univalve or an opened bypass valve is that there is not enough oil movement in a since hard over to hard over turn of the wheel to push entrapped air all the way out of the system. You reach the stop before the air has made it all the way out. So all you end up doing is shuttling the air bubbles back and forth in the system.

Note that the instructions say it can take 15 minutes worth of wheel turning to push out all the air. Just keep turning and turning in the same direction until the oil level is stable and no more bubbles are coming out. Then go in the other direction. Then go to the next helm location, and also do the same with the AP pump, running it continuously in one direction for a while, then the other direction. And pay heed to the suggestions on a fill tube and reserve of fluid so bubbles come out, but fluid gets sucked back in, not air.

Capt Kangeroo said:

OB, what type of fluid are you using in your system? I've been using tranny fluid. My book called for dextron 2 or 3 but I note on the later helms they say specifically not to use tranny fluid.

Click to expand...

I am using Dextron III transmission fluid.

We use Sea Star fluid, although we've never had to fill it.

I can't thank you guys enough for all the help, when I got up this morning my plan was to rip the whole thing out & buy new helms but you all have convinced me to try bleeding one LAST time.

Last night in preparation to bleed the system I opened the bleed screws on the univalve then a few moments later I headed to the bridge where I was greeted by rivers of tranny fluid streaming across the bridge floor to the drains then all down the sides of the cabin and onto the gunwales. I was stunned, how in hell could nearly all the oil in the system run up hill nearly 20ft and pour out the vent by simply opening the bleed screws???. What a %#&*$ mess. While contemplating my misfortune over several scotches I was determined to relegate these helms to spare anchors. Hard to believe such a simple system can cause so much grief.

t.t If this last system bleed goes south, I may soon have the same system as yours.

P.S. Clectric, if your typing skills are like mine & you typed all that out with one finger, you my friend are a saint. Great advice & time well spent that not only greatly helps me but almost certainly countless others over the years to come. Incidentally, I was using the permanently mounted dish & tube off the top of the vent to catch the overflow which would then be sucked back in during operation. It was the only way I have been able to use my steering. For bleeding I have been using a funnel but I like your idea of a jug.