Vetus Hydraulic Steering

garyohv · 04-27-2012, 02:39 PM

FYI...an exploded view of your pump and hydraulic system.
http://www.datahidrolik.com/download...imKilavuzu.pdf
Inspect the rotor screw 14.
I would isolate the stations and non-return valves (check valves) so it is a single station steering and test again.

Wireless · 04-27-2012, 06:15 PM

thank you "Gary?" for your reply. I'm going to take some more time to review the drawings but wanted to thank you for your interest and help right away.
Unfortunately my German is weak and the drawings do not illustrate the particular Vetus pumps I have. I do have the drawings and model numbers etc but can not share them now as I am only barely computer literate.
I can say that the non return valves are integral and that there are no adjustment points or check valves external to the pump.
I saw the pump in its disassembled state and the only operator service point is the top of the reservoir.

garyohv · 04-29-2012, 02:14 PM

Try: http://www.datahidrolik.com/EN-En/ou...%20Systems.asp or use just the name.com and go to Downloads.

Draw your system.
1. Which autopilot? Does it have NRV? Isolate it from the system and test.
2. When turning a helm pump, it first selects a port to feed, and second, as fluid enters the NRV, opens both the feed and return ports. It has a O ringed piston inside sliding to open ports. It seems your pump/porting is slow to pressurize...sugesting, besides air, a leaking valve, piston, or port.
3. If both pumps "slip" one might assume it's not the pumps, but it could be one affecting both. Strange, but the 2 pump diagrams show the ball in the NRVs in a different position....one is wrong.
4. Something simple could be the problem...such as the cly. mount plate bolts.
Cap off auto pilot first (at the T fitting). Then a helm pump. Test one pump or section at a time.

Wireless · 05-02-2012, 11:59 AM

Thank you Garyohv for your comments. they inspired me to keep searching. buried in the darkness behing the pilothouse icemakers I found a dual station non return valve along with the helm pressure equalization line. Sounds like this is the most likely culprit so its coming out today bound for the repair shop. A messy proposition given that its barely reachable but if its the problem then its worth the effort.

garyohv · 05-02-2012, 12:47 PM

If you are going to remove the NRV without draining, seal the upper vent cap or replace it with an unvented cap to slow the drain rate.
The only part to replace inside is an O ring.

Wireless · 05-02-2012, 01:07 PM

I'm not onboard but from memory...
the nrv seems to have two bottom ports running to inside steering station, two top ports running to the outside (highest) steering station and two center-back ports running to the cylinder. There are two unused ports on either side. The balancing line runns just behind the valve but not through it.
The unit is a five inch by five inch box three inches thick.
Getting anything under it to catch drips is going to be a *****.

Given the history of what I've done so far This would seem like the next logical step?

Wireless · 05-16-2012, 07:25 AM

So, without re-listing everything I've already checked, let me add that once the dual station non-return valve was returned and reinstalled I capped off the lines to the autopilot, purged the system, closed the bypass loop and presto, there it was, that annoying "skip" in the helm when direction was changed.

I can see where there is anything else to check in the system except for removing the pin in the tiller head to see if its in the cylinder or the rudder itself. The rudder turned freely while disconnected during our recent haulout but...

Capt J · 05-16-2012, 10:06 PM

Quote:

Originally Posted by Wireless

So, without re-listing everything I've already checked, let me add that once the dual station non-return valve was returned and reinstalled I capped off the lines to the autopilot, purged the system, closed the bypass loop and presto, there it was, that annoying "skip" in the helm when direction was changed.

I can see where there is anything else to check in the system except for removing the pin in the tiller head to see if its in the cylinder or the rudder itself. The rudder turned freely while disconnected during our recent haulout but...

Are you sure a line isn't connected to the wrong side of the other helm station?

Wireless · 05-17-2012, 07:41 AM

Both helm pumps work function and move the rudder in the appropriate direction with the same "skip". Had the outside helm out and overhauled. Since it did not help I balked at removing the lower unit since it is in a difficult to reach area surrounded by wiring.

Gary asked about the re-chroming of the cylinder. It had minor pitting on it and was assumed to be the reason for a small leak at one of the seals. The unit was chromed and machined with seals replaced. Did not improve the feel but did eliminate a pint- per- month leak.

Planning on cutting out the pin this morning if the rain stops long enough to get to the lazerette.

Capt J · 05-17-2012, 08:16 AM

I ran a yacht that had a single station and it was ratcheting in one direction, but it was supposed to feel like that and always felt like that.........it turned but you could feel a slight ratcheting resistance........how bad is the ratcheting?

Wireless · 05-17-2012, 10:05 AM

this boat has two stations, both vetus pumps. The top one is outside with a vented cap. The lower one is inside with a solid cap. There is a balance line between the two.

The racheting is the same at both stations. It occurs in both directions regardless of where the cylinder is. It happens only when changing direction. There are about four skips of about five degrees or so resultiong in about a spoke before the helm feels normal. It will happen again as soon as the wheel is reversed.

Very hard to enjoy steering and especially frustrating when trying to sail a big heavy undercanvased boat in light winds...

Peter

Wireless · 05-17-2012, 07:13 PM

Tomorrow morning the pin gets cut off of the tillerhead. When the cylinder was removed for rebuilding it was threaded off of the terminal eye. The cotter pin came out easily but the pin will not budge and is most assuredly worn into a shape other than round.
Maybe the missing link.

rcrapps · 05-18-2012, 03:37 AM

Quote:

Originally Posted by Wireless

Maybe the missing link.

Or the noise maker? When the cylinder was off did the connection (at pin) feel loose or was travel on the tiller arm connection stiff?

Wireless · 05-24-2012, 08:29 PM

Took out the pin, dropped the tiller and found the rod-end eye was frozen and would not articulate. What a relief to finally find something obviously wrong! Except that wasn't it! Put a new end on, put a new pin in, put everything back together and "Click, Clack, clunk!" ****.
The only component left is the inside helm pump which is going to be difficult and messy to remove.
To add insult to injury, the helms are now several times more difficult to turn than previous to my explorations.

Wireless · 06-21-2012, 07:08 AM

just to close the door on this one for the hundreds of people who have been following,

Hauled out again and dropped the rudder. We put a 50 ton port-a-power into the aperature and spread it open by pushing the skeg down about 3/16". Replaced both top and bottom bearings. The rudder post has a coupling to facilitate removal so we removed the top half and turned the portion where the packing seats on the lathe. Replaced the packing with teflon and threw it into the water.

Results? Finger tip control.

Having a smooth reliable steering system, priceless. The rest, Mastercard.