posted 07-07-2003 01:05 PM ET (US)        

When we were bleeding the system I noticed that one of the little allen-head bleeder screws had started to strip. It will still tighten - but not to the point where it stops completely.

Since the bleeder screw was secure, and it did not appear to be leaking, I took the boat on a fishing trip. Over the course of the weekend the steering became increasingly sloppy. Now I feel considerable slipping & skipping as I turn the wheel.

There is no sign of leaking hydraulic fluid at the helm or at the cylinder aft, and the problem screw is still snug (although it's easy to turn with an allen wrench).

The visible portions of the hoses look like new.

I'm guessing that the screw is gradually allowing air to sneak in to the system. Any thoughts?

posted 07-07-2003 02:01 PM ET (US)            

What you are describing could be air having gotten back into the system, but it also acts "sloppy" if the fluid level is simply low. If you can't find any evidence around the bleeder valve of loose fluid, I'd suspect you never got your system completely bled.

Those bleeder valves are threaded against an O-ring to develop a seal; you might want to pull the valves all the way out and inspect them for good O-rings. I'm not too sure teflon will get you where you want to go, but it might. Be sure to use teflon tape for petroleum products if you go that route, and be careful you don't lose any of it into your hydraulic system. Those threads are straight machine threads, not tapered pipe threads; I would wonder if you couldn't heli-coil an over size hole back to the original bleeder valve size if it is the female thread that is bad (and I assume it is as the valve is stainless).

John

posted 07-07-2003 02:05 PM ET (US)            

It there a downside to tapping for a screw one size up and then fluhsing the oil out through the hole to make sure nothing is left behind?

posted 07-07-2003 04:27 PM ET (US)            

Are you working from a written set of directions when you bleed your system? There is a specified procedure and a definite order in which each step of the procedure must be taken. Let me know if you'd like me to scan my Seastar bleeding directions and e-mail them to you.

I would be concerned that without a bleed valve nipple that you can attach clear tubing to in order to see when the bubbles are gone, it would be difficult to keep from introducing air back into the system when you screw a simple machine screw back in.

posted 07-07-2003 06:22 PM ET (US)            

I didn't see your first response before sending my last, so I was off the mark even more than usual.

I do have the Sea Star written instructions. They include directions for systems like mine. (My system came without the bleeder nipples). I followed the instructions to the extent that I could, but I had a kid for a helper, and I'm not certain he was able to apply enough resistance to the steering shaft during the purging process.

The steering wasn't perfectly smooth when I was finished with the installation, but it was wonderful compared to it's present condition. I assume that the steering would not degrade through use if it was not either losing fluid or introducing new air. Is that a correct assumption?

posted 07-07-2003 10:57 PM ET (US)            

If, your bleeder valve is leaking and you can positively isolate that leak, teflon tape at the top of the machine thread will probably fix your problem. If, you are unsure about your bleeding procedure you should maybe think about just bleeding the system again.

Teflon tape is harmless when used properly and CANNOT get into any brake/hydralic lines when used accordingly.

posted 07-08-2003 10:55 AM ET (US)            

I have about 20 hours on the boat since I installed the new hydraulic pump. The steering is gradually becoming less and less responsive. I can feel larger slips in the wheel as I turn it now, so she's on the trailer until I get this properly fixed.

1) Doesn't the worsening condition suggest a leak of some kind? (As opposed to inadequate bleeding the system twenty hours ago.)

2) How does a hydraulic steering system behave when the cylinder needs to be rebuilt? Is there some sort of diagnostic test I can perform to determine if my cylinder is Okay?

3) Is it possible to tap the cylinder and retrofit some type of hydraulic bleeder valve?

Thanks for your help guys.

posted 07-08-2003 11:55 AM ET (US)            

I'll answer the part(s) of your questions that I can-

The worsening needs to be accompanied by some evidence of fluid leakage somewhere in order to be something *other* than either inadequate initial bleed or failing cylinder seals. There are only so many spots leakage can occur, and I should think you would easily be able to physically look at each one and see if there is any hydraulic fluid showing up. If air is coming in, fluid is going out.

I don't know how hydraulic steering acts when the cylinder needs rebuilding or replacing, but I would expect that it would act "lazy", that is you wouldn't get a one-to-one ratio of turning the wheel to turning the engine; when you come to the end of the motor's travel in one or both directions, I'd think you'd still be able to turn the wheel, but probably with more effort than when within the motor's travel.

I should think with proper care you could retap the cylinder, but I will bow to higher levels of expertise on this one. As you have already stated, the concern would be keeping the drillings etc. from contaminating the cylinder. What do you have at your bleeding fittings now? Is it just an allen head screw, so when you remove one any fluid that comes out just runs down the surface of the cylinder? Are they inset with a shoulder and O-ring seal?

posted 07-08-2003 12:59 PM ET (US)            

My fittings are simple allen-head machine screws. There are no nipples, and they have no o-rings. When I bleed the system the fluid does just drain/squirt out the hole.

I do not know how old the system is. The portion of the hose that is visible inside the console looks shiny and new, but the pump I replaced looked pretty old. The Honda motors are 2000 model year, but the steering system may well predate them.

On my next break I'm going to price a new cylinder... ouch...again.

posted 07-08-2003 03:59 PM ET (US)         

I am also wondering if your higher capacity helm pump, resulting in the fewer wheel turns, is the problem with the older cylinder. That system is really only recommended for high speed installations.

posted 07-08-2003 05:43 PM ET (US)            

All excellent information above. The first thing I would check is the fluid level in the helm pump. It should be within a 1/4" of the top. If not, then you probably have a leak somewhere, assuming it was full when the initial bleeding was done.

My bleed screws are the same 5mm allen head with no seals or 0-rings. Both had been leaking slightly and when I installed a 20 degree wedge at the pump I used the Loc-Tite hydraulic thread sealant on the screws AFTER threading them in part way. No more leaks.

Teleflex recommends completely removing the bleeder screws rather than just loosening them when bleeding the system.

posted 07-08-2003 09:18 PM ET (US)            

Geeze. It didn't even occur to me that there might be a compatability problem as a result of higher operating pressures. I just assumed that the steering would be slightly more difficult as a result of a lower mechanical advantage, but I know next to nothing about hydraulics.

The existing cylinder is mounted outboard of the starboard engine. The cylinder is in line with the "tilt axis" of the motor. It is "converted" into a dual engine system only by a tie bar assembly that connects the two engines - but the hydraulic cylinder communicates directly only with the starboard motor.

posted 07-08-2003 10:10 PM ET (US)            

The Teleflex literature gives good information on how to bleed the system properly. It also gives good diagnostic information, too, on how to observer changes in fluid levels in the pump as indicators of air in the line.

I highly recommend wearing disposable latex gloves when working with hydraulic systems and bleeding them. The hydraulic oil likes to escape from the system about as easily as gamma rays come out of plutonium--that stuff gets all over your hands in a hurry.

posted 07-08-2003 10:34 PM ET (US)            

If memory serves, I originally had a 1.7 cubic inch pump and I upgraded to the 2.0 cubic inch displacement model. Is the "pro" the 2.4 inch model? I'm not sure.

I remember digging in this area extensively, and I was confident about my decisions at the time I made them, but I've done an awful lot of purchasing and building since I bought that pump. I'm not confident that my memory is correct - but I'm pretty sure I didn't buy the pro model. I'll check when I get back to my paperwork. (The paperwork is in my buddy's barn about ten miles from here.)

I can't see any external evidence of a leak in my system, and the hoses appear to be in great shape, so I leaning towards rebuilding or replacing the cylinder. The rebuild kits are available - but then I still wouldn't have the new bleeder valve nipples...

I'll probably just bend over and buy the upgrade. That's what I've done the last twenty times I've been presented with a similar choice. Hopefully I'll run out of upgrades before I run completely out of dough...

Thanks for all the wonderful advice. You guys are great!

posted 07-09-2003 12:31 PM ET (US)            

I can not see any evidence of a leak, but I can not guarantee that the system has not leaked. That is, the allen heads are in an area that is regularly bathed by water when the boat is being used, so it's possible that very small amounts of fluid have escaped while I was running the boat and the evidence of the leak washed away.

The hoses at the helm are dry and shiny.

I can not speak to the condition of the hoses running through the tunnel, as I have not removed them.

posted 07-09-2003 05:03 PM ET (US)         

I believe the proper helm for the single side mount cylinder is the Sea Star I, with the 1.7 capacity. The Sea Star HP (Pro) is the 2.0 capacity, and I believe is only compatible with the front mount cylinder and not for twin engine use. The Sea Star II is the 2.4 capacity pump, for twin cylinder installations on twin engines, either side or front mount cylinders.

So, yes, you may have a compatibility problem. That helm may be overpressurizing the cylinder. I would call Teleflex in Vancouver.

The reason BW furnished the side mount cylinders on the WD boats was for tilt-up clearance. However, if the engines are mounted all the way up on the WD, as they should be, you may still have enough tilt-up clearance using the new front mount cylinder. New tie bar design will be required.

posted 07-09-2003 05:33 PM ET (US)            

I originally e-mailed Al last February because I needed his help identifying the pump I had, and I needed some advice on how to improve my performance. At that point I was primarily interested in reducing the number of turns it took to move from hard right to hard left. Al diagnosed my original pump from my description. (You're right Larry. It is a 1.7) Al directed me to the 2.4 pump and I bought it. There are no compatibility problems as the operating pressures of the three pumps we spoke of are either the same or nearly the same. In fact, my receipt from Go2 Marine actually shows the relief valve pressure settings for the 1.7, 2.0, and 2.4 systems. They are all set at 1000 psi.

I just e-mailed Al with this updated dilemma and asked for his thoughts. I'm hoping to hear from him soon. I'll share whatever Al tells me with you guys.

posted 07-10-2003 02:39 PM ET (US)            

The symptoms I described are not consistent with a bad cylinder, which is usually marked by hydraulic fluid leaking AT the cylinder. If I can't see a leak, it's probably Okay.

Mark explained that the 5370-71 is an unbalanced system so, if the system was incompletely purged, it would be possible for air to "hide" in the cylinder and gradually migrate back to the pump where it would increasingly degrade the power steering.

To test for air in the system Mark instructed me to do the following: "Walk back to the motors and see if you can manually push the motors from side to side. Any movement, even a quarter inch, suggests that there is air in the system." Unfortunately, my motors weigh 505 pounds each, so they are not prone to move, but I'm going to try the test and re-bleed again anyway.

The nipples can be retrofitted, so I'm probably going to order a set...

posted 07-12-2003 11:32 AM ET (US)            

The leak was extremely difficult to find, because it only shows up at the extreme end of the turning range. Even then the leak isn't visible from the helm, and it leaves no evidence behind, as it is a tiny pin-like spray that vents aft. As soon as the steering pressure is released, it stops spraying, and there's no sign that it leaked!

I found the leak by having my son turn the wheel as I stared at the fitting - and I still would have missed it if I hadn't been right on top of it. The spray was so fine it turned into a mist a few inches from the fitting. (Which also explains why it took two weekends of use for the steering to degrade to it's present condition.)

I'm ordering two new "Horizontal Bleeder Tees" today.

posted 07-12-2003 11:03 PM ET (US)            

The bleeder Tees should make bleeding my system much easier in the future, as you can shut down the bleeding while the bleeder screw in still surrounded in oil, thereby minimizing the opportunity for air intrusion.

Since the Tees screw directly into the cylinder, and the new bleeder screw assembly is part of the new Tees, I will not have to do any tapping. The convenience and upgrade are worth the $37.

posted 07-15-2003 10:59 AM ET (US)            

The system does have a reservoir at the helm pump, so it will tolerate some loss of hydraulic fluid before the steering degrades noticeably. Since my system lost fluid at a cylinder fitting only when it was under higher pressure, the fluid level at the helm dropped very slowly. The steering degraded gradually at first, but it got worse very quickly on our last trip in to port - presumably because, near the end, the oil in the reservoir had been exhausted and each turn of the wheel was introducing MUCH more air.

Maybe your helm was low at the end of the season, but it had yet to get to the critical stage.

posted 07-17-2003 03:54 PM ET (US)            

The installation and bleeding only took me about 20 minutes. Now the steering is as smooth as glass. Lock to lock now requires about 3.6 turns in one direction and 4.25 in the other. (That's the next thing to figure out. Work keeps getting in the way of my boat repairs.)

posted 07-17-2003 09:43 PM ET (US)            

Larry, I've ingested a great deal of information in the last 10 months, but I'm afraid much of it has slipped through the cracks in my brain. You're right, the information is right there in front of me in the reference section, no doubt absorbed and lost at least twice in the last ten months. I'm hoping it will stick this time.