Steering: Which component is the problem?

I have a 1984 Trawler with hydraulic teleflex system. 3 pipes to both helms and a teleflex 50 Uniflow valve.

Here's my problem: Making slow corrections on the wheel makes NO corrections on the rudders. Making quick jerky movements on either helm produces desired rudder movement.

Also, when the autopilot is engaged, when it makes a correction to port, one or both of the wheel move slightly to Stbd and vice-versa.

This leads me to suspect that the Uniflow valve may be the likely culprit and is allowing fluid to leak past the appropriate one-way valves when moved slowly but when the pressure is higher during a fast wheel correction it overcomes the leak-by (my invented term) and actually does something.

Any wise old birds with experience to either confirm or refute my theory would be appreciated. From what I understand these systems are decades obsolete and cannot be replaced other than changing both helms ($$$$$$$$$$)

The first problem sounds like there is air in the system and you need to bleed it out. The issue with the autopilot I sure about.

Is the reservoir filled to the correct level?

Dirt in the check valves inside the helm pumps is #1 cause, #2 is the top helm needs a little oil. Both an easy fix just a little time and oil........

Wow, that was fast!

OK so...

1) Capt Bill, how do you bleed the system?

2) Meridian: If you mean remote reservoir tank, I don't have one (although my mechanic swears there should be one somewhere). If you mean the helm itself, I haven't opened up anything yet to check levels.

3) Roche: How would you go about "cleaning" the system?

With the Capilano system there is no reservoir other than the helms themselves. The Uniflow valve is a set of shuttle valves so the cylinder has a return path to the helms whether going to port or to starboard. The helms do not have check valves as the uniflow eliminates the need.

here is some more data

When I talked to the great guys at Teleflex across the "pond" they told me to remove the hydraulic lines on the sides, then remove the fitting the lines attach to(in my case the 90 degree ones). Once the fittings are removed you will see a light spring that has a steel ball behind with a case and o-ring it on each side. Clean the ball, spring and the seat the ball sits in. On our boat the autopilot cause the upper helm to turn as it pump fluid.

They sell new springs, balls and cases but he said it is rarely needed unless the parts are damaged.

See the attached PDF they sent me. Worked like a charm with no parts....

And more......... See Summary of the invention.

Rochepoint

Your PDF is for a newer helm. The older helms with the univalve do not have ball checks.

obthomas
I have 1985 helms with the univalve and it has exactly what the PDF shows......

Rduval

Take care of your univalve 50; they are no longer made. There are repair kits however. If the univalve ever goes bad and you want to eliminate it you must put in new helms like Rochepoint has that have the check valves.

Rochepoint

I do not doubt what you say is what you have. Read the univalve attachment that I posted earlier and note on the summary of the invention that the purpose of the univalve is to eliminate check valves at the helms and to put it in one place in the univalve. I have the old helms and they do not have the check valves. You can explain better than me why you have both a univalve and newer helms.

Just the way the boat came and when I talked to Teleflex there knew what I have.

Plus one more item that I did not ask them about, here a photo of it:

Rochepoint


Looks like a manifold for two steering cylinders. I do not have one because I have only one steering cylinder.

obthomas said:

Looks like a manifold for two steering cylinders. I do not have one because I have only one steering cylinder.

Click to expand...

I should have said that it mounted between the upper helm and the autopilot pump.............

Oh. O.K. it probably the check valves for you autopilot pump. Looks to me like your set up has all the necessary stuff to eliminate the uniflow.

rochepoint said:

obthomas
I have 1985 helms with the univalve and it has exactly what the PDF shows......

Click to expand...

Yep, exactly the Valve and helms I have (as you would expect since we have the same boat but yours is one year newer)

rochepoint said:

Just the way the boat came and when I talked to Teleflex there knew what I have.

Plus one more item that I did not ask them about, here a photo of it:

Click to expand...

Whoa! I don't have one of those on mine (at least not that I know of).

My Univalve and Autopilot pump are located right above and beside (respectively) the actuating ram. Where is this mystery valve located? In the same area?

Rduval said:

Whoa! I don't have one of those on mine (at least not that I know of).

My Univalve and Autopilot pump are located right above and beside (respectively) the actuating ram. Where is this mystery valve located? In the same area?

Click to expand...

Our Univalve is located above our actuating ram, the other component is located next to the upper helm on the command bridge as is the autopilot pump....

Rochepoint: I see you also have shut off valves in the picture. Are they just there to isolated the autopilot for bleeding the system?

Sorry Rick
I have no idea as to the valves use, have never had to bleed the system.

Rduval said:

Wow, that was fast!

OK so...

1) Capt Bill, how do you bleed the system?

Click to expand...

If you read the PDF of the owner manual it tells you how to purge the system.

Capt.Bill11 said:

If you read the PDF of the owner manual it tells you how to purge the system.

Click to expand...

Yep, I saw that, thanks.

I spoke to Teleflex via email and they said to isolate the Autopilot pump to do some testing, I was just wondering if that's what the valves accomplished instead of removing and capping the lines temporarily which I imagine is pretty messy.

Their suggestion is to "flush" the system to get rid of dirt. Not sure how to go about that other than drain and refill, repeat, repeat, etc.

I just finished overhauling my uniflow valve with their o-ring kit, aside from the mess taking the valve out it is a very simple process. I did not totally disassemble the valve but I now wish I had just for the peace of mind. From what I can see of the patent drawings, it would be a simple and inexpensive task to have a machine shop make replacement parts for the valve if ever needed.

When I get back to the boat the next task is replacing the seals in both the helms and both ends of my cylinder. I flushed my system and put in new tranny fluid and my previously bone dry system started to leak everywhere.

Apparently the replacement for the 250 and 275 helms are models 1250 & 1275.

What I don't get however is that the pdf's from Mike & Ob specifically show the 250/275 (at least the document says its for the 250/275) as having check valves behind the outlet fittings and also internally???? It was my understanding the model 250/275 helms do not have check valves, only the newer 1250/1275 models.

Incidentally, I also do not have that extra manifold that Mike has.

RDuval, the flush procedure as you described is how I did mine X 2 and I discarded the flushed tranny fluid. $$$$$

No need to remove & cap lines to pump, you "should" have two ball valves near your autopilot pump which you can close to isolate it from system.

When you bleed the system, make up a good sized funnel with a clear tube attached to the end of it, on the other end of the tube attach a hose barb to 3/8 male npt fitting. This screws into the air bleed on the top of the upper helm. DO NOT fill the funnel more than 1/2 way when bleeding. Have lots of paper towel handy. I used a funnel with a shut off in the neck, makes it easier to dump extra when system is full.

Capt Kangeroo said:

RDuval, the flush procedure as you described is how I did mine X 2 and I discarded the flushed tranny fluid. $$$$$

No need to remove & cap lines to pump, you "should" have two ball valves near your autopilot pump which you can close to isolate it from system.

When you bleed the system, make up a good sized funnel with a clear tube attached to the end of it, on the other end of the tube attach a hose barb to 3/8 male npt fitting. This screws into the air bleed on the top of the upper helm. DO NOT fill the funnel more than 1/2 way when bleeding. Have lots of paper towel handy. I used a funnel with a shut off in the neck, makes it easier to dump extra when system is full.

Click to expand...

Nope, no ball valves..Grrrr. I searched the parts stash on the boat and found a piece of clear tube on a fitting as you describe. I'm assuming that's what I'm looking for. The only funnel that fits in the hose is very small; think I'll go looking at Canadian Tire or UAP to day to find a larger one and one with a shutoff as you describe, that's a great idea.

Teleflex suggested I disconnect the hoses at the ram and drain the whole system then refill the helm and turn the wheel only one way until at least one full bottle (litre/quart I presume) has been flushed through then do it again turning the wheel only the other direction and then do the full refill/purge procedure as described in the manual.

I wonder if it's worth taking the check valves in the side of the helms themselves out while it's drained to make sure they are clean or if flushing the system will take care of that?

Just an update for posterity...

I drained and refilled the system as suggested by Teleflex. I opened the flathead screws on the sides of the Univalve - NO MORE THAN 2 FULL TURNS! - (Not sure why but the manual was VERY specific about that). Then you can turn the helm in any direction without pressure going to the ram and you can turn it pretty fast which is what I did. I think the high speed of the fluid helped to "wash out" any dirt in the check valves at the helms.

I also removed the upper fittings and check-valve springs in the side of the upper helm (it was easy to get to unlike the lower) but the balls did not come out or anything else so I just put them back together and did the refill and purge procedure rather than fiddle around (and possibly damaging) the checkvalves.

After refilling from the upper helm (with the funnel connected to a piece of clear hose and the screw in fitting) and letting the air naturally purge until it remained constant for a minute or so I ran the autopilot pump first to purge the air in there (lowest point) by setting the autopilot to AUTO then commanding turns first in one direction then then other a few times as the pump whirred away and purged itself.

I then went to the lower helm and turned the wheel continuously and as quickly as I could in one direction for a couple of minutes and then in the other for a couple. Again to flush dirt as well as purge air. Just make SURE you keep the fluid level up in the top helm or you will introduce air back into the system.

Then do the same with the upper. I then used a small hand pump used for transferring fluids to suction excess dexron fluid out of the funnel and a little from the helm to allow for expansion. Used lots of paper towels cleaning up the mess afterwards.

Bottom line... It worked.

Thanks to all and hope this helps somebody else.

Art just take all the air out and and replace it w fluid.

Now that I've had my SA moment Teleflex gives out very good advice.

Rduval, You didn't happen to note the model number stamped into the side of your helms did you? I'm still baffled why your helms supposedly have check valves yet you have a uniflow. When you took the fittings off the upper helm could you actually see the check balls in there?