AutoNav Autopilot Hydraulic pump leaking

[CLady]

After 16 years of perfectly reliable service, through thick and thin, my boat's Type 2 AutoNav Hydraulic pump for the AutoNav hydraulic ram driving the steering quadrant is leaking fluid. I'm guessing there isn't any way to fix this sealed cylinder.

Are there compatible replacement reversing hydraulic pumps? The hydraulic ram is just fine. Only two wires connect to the pump from the autopilot computer controller-- hot and ground.

I saw a pump called "Octopus" on line, good for type 2 with 12" ram throw.

???? Help??? ????

Of course this happens just after new bottom paint, new steering cable/chain installed on quadrant, after dilligently dropping the rudder to inspect post/rudder post tube, etc. and service.

[Wainui]

Octopus make good pumps and their backup service is excellent.

[Jim Cate]

Before giving up on the original unit, take it to a professional hydraulics shop for evaluation. Most things hydraulic are repairable.

And on the side: we have an AutoNav 150 which has suffered from excessive hunting from birth... never able to cure it and only have it as a backup now. Did your unit have such a problem?

Jim

[svadagio]

I have autonav and replaced the pump with octopus. works great.
Bob

[CLady]

Thank you ALL for your quick and helpful replies!
Yes, the hunting was a problem until a friend of mine got the settings right, BUT, in light conditions, nothing would stop the hunting.

I'm readying to do some offshore racing singlehanded again and need to quickly get this sorted out. I'll take the pump to see if it can be fixed. If not, I'll get the Octopus unit--it looked like a good fit for my application/setup parameters.
Thanks again!
CLady

[Canuck Sailor]

Icicle is equipped with AutoNav 1500 for over 20 years and I had a similar problem with a brand new original pump, had it replaced and same problem. Replaced it with two Octopus pumps.(not at same time) I use a 1.2 litre pump for light conditions and powering and a 2.0 litre pump for heavy winds conditions. The amp draw helps reduce overall amperage as well.
Hunting is strickly setting adjustments in any kind of weather.
I have a double pole double throw(DPDT) switch that can be changed over at any time I see fit. The wiring is not negative & positive per se, it is reversable and changes as needed by the server.
I have had problems with my system but I am still using the server that I purchased 20+ years ago and ended up with a Nexus 1600 as a spare but don't like it as much as the 1500 AutoNav. I purchased the replacement after a skipper faux pas but quickly put the old unit back when it was checked out.
I use the complete system with Nexus Sailing Instruments.

[CLady]

Hi Canuck Sailor--
Wow--you really got it dialed in! Having two different pumps would be awesome. I'll be cruising PNW and B.C. next year and need to have A.P.s (incl backup) sorted out.
Thanks,
CLady

[Canuck Sailor]

Octopus pump caution.

Only problem I have had with my Octopus pumps was a screw backing out and spraying ATF all over the engine room. Loss of hydraulic steering/AP/manual steering ensued. I was able to retrieve the screw and replace hydraulic fluid, bleed and get underway again. Naturally, it happened at night and during a 4 day crossing.

Solution.
Align all three screws with slots vertically(in line) around the pump and seize with a stainless steel wire. This way the screws can not back out. I believe the normal adjustment is 1-1/4 turn out but aligning them I think is more important. Both of our pumps now have seizing on them.

[bsurvey]

not sure why you can't take the ram to hydraulic shop and have it rebuilt it is typically a seal that leaking??

[RolfP]

I too have an AutoNav pump with my Nexus. I had a leak too. It was the reservoir where it attached to the pump, some kind of old cork or rubber or something. I replaced the reservoir with one I.found on line, I had to buy three to hit the $50 minimum at 17 apiece, but it has been working fine since. I plan to have it rebuilt at a hydraulics shop some day. Some day. Someday. Hmm. Like aLot of other things.

If it turns out that it's the reservoir I have an extra.

[NahanniV]

Originally Posted by Jim Cate

.....
And on the side: we have an AutoNav 150 which has suffered from excessive hunting from birth... never able to cure it and only have it as a backup now. Did your unit have such a problem?

Jim

I had a problem with excessive hunting on a new Comnav (autonav/silva/nexus) 1500 autopilot on my old boat around 2000.

Endless calls and emails, settings were part of it, but not all.
Finally got lucky and was able to talk to an engineer at Comnav in BC, he said the problem was because of play(backlash) in our drive system (Whitlock rotary) he had also encountered the same problem with leaking hydraulic bypass valves.
The solution was to add some resistors into the rudder feedback cable (sorry I can't remember the exact details).
That solved it completely.

Good Luck,
JM.

[Jim Cate]

Originally Posted by NahanniV

I had a problem with excessive hunting on a new Comnav (autonav/silva/nexus) 1500 autopilot on my old boat around 2000.

Endless calls and emails, settings were part of it, but not all.
Finally got lucky and was able to talk to an engineer at Comnav in BC, he said the problem was because of play(backlash) in our drive system (Whitlock rotary) he had also encountered the same problem with leaking hydraulic bypass valves.
The solution was to add some resistors into the rudder feedback cable (sorry I can't remember the exact details).
That solved it completely.

Good Luck,
JM.

Why, thank you very much for that! As it happens, we also have a Whitllock with some backlash in the drive, and that did seem to exacerbate the problem. Putting the steering brake on in light conditions helped somewhat, but idn't cure the issue. I'm having a hard time understanding the use of resistors in the feedback loop... the position sensor is a simple potentiometer, so adding the external resistors in series would just tell the computer that the rudder was in a different position. PErhaps the resistors were in combination with a capacitor, making a RC damping circuit... I dunno, but if you could dredge up any further details, I'd be grateful.

I have kept the Autonav installed but switched out of service, to be used if our Navman 3100 should fail. It would get us home, but having it not do the hunting would be a real blessing if that should happen.

It was a shame that the mfg never made a fix public, for the hunting was a common problem with Autonav, and otherwise it was a good a/p.

Thanks again for posting.

Jim

[NahanniV]

Originally Posted by Jim Cate

Why, thank you very much for that! As it happens, we also have a Whitllock with some backlash in the drive, and that did seem to exacerbate the problem. Putting the steering brake on in light conditions helped somewhat, but idn't cure the issue. I'm having a hard time understanding the use of resistors in the feedback loop... the position sensor is a simple potentiometer, so adding the external resistors in series would just tell the computer that the rudder was in a different position. PErhaps the resistors were in combination with a capacitor, making a RC damping circuit... I dunno, but if you could dredge up any further details, I'd be grateful.

I have kept the Autonav installed but switched out of service, to be used if our Navman 3100 should fail. It would get us home, but having it not do the hunting would be a real blessing if that should happen.

It was a shame that the mfg never made a fix public, for the hunting was a common problem with Autonav, and otherwise it was a good a/p.

Thanks again for posting.

Jim

It was two equal resistors if I remember correctly (I will look for my notes).

[NahanniV]

Originally Posted by Jim Cate

Why, thank you very much for that! As it happens, we also have a Whitllock with some backlash in the drive, and that did seem to exacerbate the problem. Putting the steering brake on in light conditions helped somewhat, but idn't cure the issue. I'm having a hard time understanding the use of resistors in the feedback loop... the position sensor is a simple potentiometer, so adding the external resistors in series would just tell the computer that the rudder was in a different position. PErhaps the resistors were in combination with a capacitor, making a RC damping circuit... I dunno, but if you could dredge up any further details, I'd be grateful.

I have kept the Autonav installed but switched out of service, to be used if our Navman 3100 should fail. It would get us home, but having it not do the hunting would be a real blessing if that should happen.

It was a shame that the mfg never made a fix public, for the hunting was a common problem with Autonav, and otherwise it was a good a/p.

Thanks again for posting.

Jim

I did find my notebook.

The first problem I had was with the compass heading periodically jumping by about 10deg. They sent me new firmware (an EEPROM) that fixed that.

The other problem was with the rudder moving back and forth for no apparent reason. It would still steer, but course keeping was not great.

I spoke with many techs and have many notes about settings, but none about the resistor fix. The settings helped with course keeping, but did not stop the extraneous rudder oscillations. Once I made the resistor fix I had no more problems. What I remember was two equal resistors that needed to be within a certain range inserted into the rudder reference circuit.

The person I spoke with was Dick in engineering phone:1-604-526-0113.
engineering@autonav.com

I think that was in 2003.

Good Luck,
JM.

[Jim Cate]

JM, again thanks for the post. From memory, we went through similar setting adjustments and did improve things a bit, but never settled the hunting issue. Our Whitlock drives via a Pittman arm and drag link to the tiller arm, much like automotive steering, and it is positive and totally reliable.

We have had occasional hunting with the new a/p, though nothing like with the AutoNav. The backlash is inside the drive. We've been in contact with the chap in the UK who services the Whitlocks, and he sent lots of info about disassembly. Ended up replacing the internal chain which had stretched a bit, and that helped a lot. There may be wear or breakage in the internal gears, and at some poiint I will attempt to address that issue. For now that would interfere with the cruising life too much, and after all, it IS working...

So, I'll try an e-mail to the address you gave. I suspect that it is long since dead, but why not try?

Cheers,

Jim