Dalump

Im working with a 1985 Wellcraft/Excalibur Cat 30' It's got dual external hydraulic steering. I had a problem last year with bad seals in 2 of the 4 steering cylinders. Actually bent the tie bar which I dont think this thing is supposed to have anyway. I rebuilt all 4 cylinders all with new seals, O-rings, etc. The cyclinders on the inside looked great, no scaring or scratches so I'm pretty sure that I'm not getting any hydraulic "blow by".

Powered her up today in the driveway and I cant seem to get the cylinders to work together (sychronized). It's driving one until it bottoms out then the next.. It's acting like there's still air somewhere in the system, but Ive bled the living sh*t out of it. Seems like all I'm doing is making a pretty big mess and really pissing off the wife.

What's the chances that the power steering pump is too small? Not enough working pressure? They guy that owned the boat before me was a total retard and "rigged" all kinds of things including the steering system. It wouldnt surprise me at all if he put an incorrect pump on this boat just to make it work half-assed.

Is there a certain procedure to follow to eliminate any air from the 80+ feet of hydraulic lines? Ive tried everything that I know how to do.. Not getting any air bubbles when I crack the lines loose.

I'm kind of stuck in the driveway with a not so understanding wife until this is resolved.

Any ideas, suggestions, instructions would be greatly appreciated.

Thanks,

Todd (DaLum)

madmax911

4 rams and a tie bar and 1 pump ?
I am no expert..but Iwould think if geometry of all the rams were not perfect they would fight each other.
As for the pump...I have a friend that had to drill out the orifice to get more flow...I will try to get him to post the size drill he used.
If it were me I would try disconnecting one ram on each side and cap the lines to see if the system worked better.
Have you called the manufacturer and got their opinion ?

Dalump

Hey Max,

Id appreciate any ideas.
The boat was rigged with Kaama surface drives so getting a hold them is out of the question. There was a member on the OSO forum last year that gave some advice on gear sets for the Kaama surface drives.. I think it was KaamaCat or something like that. He has pretty much the same boat.

I asked him about the tie bar and he said it wasnt supposed to have one because of it being below the level of the tunnel and it would drag.

Funny you should mention capping two of the cylinders.. The two rams on the inside were capped. There are external lines to the cylinders but on the inside of the transom, they are just plumbed to each other.. Nothing connected to any hydraulic pressure. Basically at that point, they are all for show and just going for the ride. I never even noticed until last weekend when I rebuilt all 4 cylinders. The two inners were dry as a bone. no fluid present. That didnt make sense, so I traced the lines and found they were connected to nothing but each other.

I installed two "T" fitting and two hyd lines and made them functional, but now cant get all 4 to move together. My goal was to do away with the tie bar if possible.

Do you think 2 rams is enough? Im a bit nervous about doing that after last year's bent tie bar.. If that should break, Id be looking at a ton of cash in potentially damaged props and obsolete surface drives.

Todd

Mbam

The 2 rams that were connected together were acting as a hydraulic tie bar. With out a connection either physical or hydraulic the behavior you describe is unavoidable (and will never steer the boat).

Hydraulic tie bars are kind of a pain, as it is hard to bleed the loop, and really hard to keep the drives aligned.

See if one of the steering guys has a plumbing diagram available.

Dalump

Hey Mark,

I can see the two disconnected rams working as a "hydraulic tie bar" if they had been completely full of fluid and the connecting lines between them bled, but the way the were, being bone dry I really dont think they were doing anything...

Who are the "steering guys" you are talking about? Id love to see a plumbing diagram. Im pretty sure that the way I have the lines run to the 4 different rams, it's the right configuration. I work with air cylinders everyday so Im very familiar with the concept. The cylinders do move in and out like they are supposed to, just not at the same time and speed.

Im going to take apart the two "slow" or "delayed" cylinders in the AM to see if there's any unusual binding internally. Other than that, Im at a loss.

Thanks,
Todd

Mbam

I agree, if empty they were doing zip.

Without a connection the cylinders will just never move together. The effective piston area is different on each end of a cylinder. The end with the rod is has less area , hence less mechanical force than the end without.

You probably do have them hooked up correctly, but without a mechanical connection they will not sync.

You can check with CP, Latham, Marine Machine, Imco (there are more but I can't think of them off the top of my head)