Steering gear system problem on a 58YF

[MarioG]

I believe I have a problem that I can't quite figure out. when I turn the wheel from "stop to stop" the wheel doesn't stop turning even though the rudder has reached it's max travel according to the rudder indicator. when reaching the end of rudder travel, the wheel just responds with more resistance but continues to turn. never reaching a "mechanical stop" in either direction. even though i just changed the fly bridge steering pump which was leaking, the problem predates the repair. currently, I have no loss of fluid anywhere and the reservoir shows full capacity. I keep about 35psi of air in the reservoir. The problem is the same at both steering stations. I have always had this problem. What could be the problem?

I have the standard factory hynautic steering system.

thanks, Mario

 

[Boatsb]

Why are you convinced it's a problem?

 

[Will]

This is only a WAG,
1. If the rudder travel exceeds your rudder indicator readings, you can correct via either an electrical or mechanical adjustment on your rudder indicator system.

2. The problem with the helm continuing to turn after your rudders reach the limits of their maximum range is caused by a hydraulic problem. There may be a check or limiting valve operating improperly, a hydraulic cylinder where fluid can pass by the piston, or a similar problem with one of your helm pumps.

Will

 

[MikeP]

You do not have a problem. There is no mechanical stop on the steering wheels - they will turn forever.

There is a pressure relief valve on each helm pump that "pops off" when the rudder reaches it's max travel in either direction. There is an increase in resistance when you reach the end of the rudder travel. That increase is the difference in pressure needed to unseat the valve as opposed to turn the rudder.

All totally normal and IAW system design.

 

[Pascal]

sure about that Mike? both helms on my 53 reach a firm lock at the end of travel. I'm pretty sure that Sanctuary's helm behave the same way, along with the power assisted hynautic helm on the 70 footer I run.

just like any other hynautic steering boat i drove! you feel a stop and you can't turn the wheel any further.

 

[MikeP]

Yes, you CAN turn the wheel further...as far as you want to turn it - you are just not trying hard enough! I've had the helm pumps apart and there is no stop of any kind in the Hynautic pumps. There can't be because each helm is totally independent. If you turn one helm wheel, the other does not turn. So, if there really WERE stops, you could end up with one helm pump (wheel) at it's stop when the rudder wasn't actually at either limit.

As an example, let's say I turn the lower helm full left to the point where it FEELS like there's a stop (the rudder is now at full left). Now I go up to the upper helm and turn that wheel so the rudder is now full right where it feels like there is a stop. NOW...go back to the lower helm. Remember, it was "stopped" at full left. IF there was a stop at the helm pump/wheel, the lower helm wheel would already be at its stop and you couldn't move the rudder left. But you can!

Now, it is possible that if the system is not well bled OR the relief valve spring is too weak, the wheel could be moving easier than it should after the rudder is at full deflection. There should be an obvious and fairly difficult "end" to the travel of the rudder. But if you just keep turning the wheel - admittedly considerable effort, it will continue to turn all day long as the relief valve opens.

THe point of the relief valve is so, when the rudder actually hits it's stop, you can't destroy it. If there was no relief valve, you could easily generate enough pressure in the hydraulic ram to either burst hydraulic fittings or damage the rudder itself.

 

[Pascal]

well, I just turned my lower helm, stop to stop a couple of times, it would take considerable amount or pressure to keep turning it beyond full rudder. I guess i could force further but it woudl be VERY hard to do so.

I know there is no physical stop in those pumps, but the pressure gets so high that it feels almost like a stop, unless you really force it further.

obviously since they're independent pumps, they will not "follow" each other!

 

[Boatsb]

The bleeder block allows the fluid to bypass when the ram is to block. That is why there is a 3/8 return line on the system.

 

[yachtsmanbill]

I agree with Mike...I replaced the "armstrong" unit on my Roamer with a upper and lower teleflex unit. After lock, it will chatter as long as you want it to. The manual unit was superior for feel, plus I made a brass headspoke which indicated rudders amidship. That was good at nite too as you can feel the brass versus the wood spokes. ws

 

[Diver Down]

We experienced the same situation a few months ago after we replaced some hydraulic lines. We thought we had bled the steering system sufficiently but the wheels at both stations would turn with one finger with no resistance in either direction. The 'problem' - and, yes I would call it a problem whether technically correct or not - finally went away after I SLOWLY turned the wheels from rudder amidship position to full port and then full starboard about 30-40 times. I guess there was still air in the line that was eventually forced out of the relief valve at the end of the hydraulic line in the lazarette.

1977 Hatteras 58YF

 

[MikeP]

Yes, it often takes considerably more than the "60" times stated in the Hynautic bleeding instructions. It took over 100 when I purged/bled my system a few years back.

I'm NOT saying that the wheel should easily turn past the rudder limit. There should be a LOT of resistance. But you can keep turning the wheel "through" the resistance as the relief valve cycles each time one of the ball bearings "pumps" the fluid. This causes a "chattering" sound/feel as Bill noted. There IS a rudder stop (of course) but there is no wheel or pump "stop."

 

[Nonchalant1]

well, I just turned my lower helm, stop to stop a couple of times, it would take considerable amount or pressure to keep turning it beyond full rudder. I guess i could force further but it woudl be VERY hard to do so.

I know there is no physical stop in those pumps, but the pressure gets so high that it feels almost like a stop, unless you really force it further.

obviously since they're independent pumps, they will not "follow" each other!

My 53my is the same as Pascal's. It's 2 3/4 full turns from stop to stop, and the stops feel like hard stops, even though they may just be from high pressure. I wouldn't try to force it.

Doug

 

[MarioG]

I do hear a chattering sound from the bridge when i turn that wheel past the "stops". the resistance I feel is just slightly more after the end of rudder travel. could it be that the system has never been bled properly in more than 1.5 years of use?

 

[MikeP]

Yes, it is possible. Again...there should be substantial resistance to turning when the rudder is at full deflection, not just a slight increase. It is possible that the relief valve spring is weak. THis, in itself won't hurt anything AS LONG as the relief pressure is substantially more than the pressure required to move the rudder.

Go through the bleeding procedures but, instead of Hynautic's recommendation to turn the wheel 60 times in one direction, followed by 60 times in the other, do it 100 times each way.

Also, be sure you understand that you are to turn the wheel 100 times to the right, then 100 times to the left...NOT back and forth 100 times. When the system bleeds completely, the resistance will increase (hopefully) dramatically and may feel like you are hitting a stop in the wheel. KEEP turning it until you have done 100 revs (each way). YOU CANNOT hurt anything regardless of how much resistance you think you are feeling and it has to be done that way to ensure complete bleeding.

 

[Fanfare]

I have the very first Hatteras to have a Hynautic steering system, which means everyone else has a newer one than me. Yours may be different. I have a bleeding block near the steering ram. It is green metal, about 4 in. long, and has three(?) tubes going into it. In its center is a hex base cap nut which covers a bleed screw. Unscrew the cap to reveal the bleed screw, which may also have a lock nut. The screw comes out about two full turns. I think this lets hydraulic fluid bypass the steering ram and passes the oil directly from the right or left delivery tube to the center return line. If you have this it surely reduces the effort to get all the air from the steering wheel pump back into the resevoir. You stilll have to take 100 turns in each direction to clear the lines. Do each steering wheel and your autopilot pump. Then retighten the bleed screw so it just barely, but firmly, sets, and replace the hex nut.

The air pressure doesn't "hold" any fluid, it just keeps dirt out and alerts you to any leak in the system.

 

[MikeP]

Unless you have lost hyd fluid in the ram, there is no need to open any screws to bleed the system. Even if you completely empty the system of fluid you don't have to do that BUT it is faster, if the entire system has been drained, to fill the ram by opening the bleed screw AFTER you fill and pressurize the reservoir.

IF you have pressurized the reservoir the only thing you have to do to bleed the entire system can be done at the helm pumps per the Hynautic bleeding instructions. This is all covered in the instructions provided by Hynautic and sometimes people treat it like manually bleeding a brake system in a car BUT the difference is, the reservoir in the boat provides fluid under pressure to the system so the helm pump will bleed all the air out just by turning the wheel a sufficient amount of times.

 

[MarioG]

OK Mike, I'll give it a shot tomorrow. Thanks to all for your help. I'll report back with the results.

Mario

 

[Brian Degulis]

Mario It should take a considerable amount of effort to turn the wheel past the stops in a good hynautic system. It feels like a mechanical stop and you've realy got to lean into it to get it to turn further. Check to see that the screws on the charging valve (normally near the cylinder) are turned in all the way moderatly tight. If that doesn't do it then I would bleed it to insure there is no air. If that doesn't do it then I would remove the cylinder and check the seal on the piston. If that seal is bad you won't see any fluid leaking but it will cause the problem your having. If that's not it then one of your helm pumps has a bad relief valve. I'm not certain but I think if a relief valve goes bad in one helm both helms will continue to turn past the stop but check that out cause I'm not certain about it.

Brian

 

[MarioG]

Re: Steering gear system problem on a 58YF (UPDATE)

NOPE! I turned the wheel a billon times in each direction. still have the same problem. the hatteras manuel says that the steering pump stations are isolated from each other, therefore if i have the same problem at both stations I am lead to beleve that the problem should be at the steering actuator. infact i now notice that a higher than displacement speeds the rudder is not moving as much as when were at slower speeds. I'm thinking about removing the return side hose off the steering actuator and see if fluid is bypassing the seals when reaching the end of travel then reverse the test with the other side of the actuator.

Am I warm?

 

[Brian Degulis]

Mario just remove the lines from the steering cylinder and plug them off. (you can buy flare plugs or caps for this) When they're plugged off you should get very little movement on either helm you should feel a hard stop. If you do that would confirm that fluid is leaking past the piston within the steering cylinder. If you don't then the problem is someplace else. Remember to de pressurize the tank and be quick getting the caps on so you don't loose to much fluid.

Brian