Dead B&G Autopilot, Blue T2 Ram

toddster

Super Anarchist
4,458
1,144
The Gorge
This weeks main problem is investigating and attempting to cure a non-functioning H2000 B&G autopilot. The manual is pretty execrable and has very little information about the hardware.

Last week, I was cruising along on a teeth-chattering day, headed down through the Columbia River Gorge. About an hour before, the boat had been bouncing around quite a bit in a nasty chop, winds 10-20 with gusts to 35 AWS. (Not in the forecast, BTW. And not super-unusual but bouncier than I usually head into on purpose.) But things were relatively calm by this point. I hit the autopilot button for a turn to port, but then realized that we were actually drifting off to starboard. Error 103 started flashing on the display.

Later that evening, when I had docked, warmed up, and gotten out the manual, I learned that "103" means the autopilot attempted to change course, but no feedback was received from the rudder position sensor.

BTW: Internet research suggests that this 20-year old unit is no longer supported by B&G. I mean, they still sell "T2 Rams" but they no longer look quite like this. However, the OEM supplier is a UK outfit called Hy-Pro and they may be more willing to support it, if parts still exist.

I verified that the RPS (the black cylinder, seen below) is working correctly. (Turn wheel port or starboard, and the rudder position is displayed correctly on the hydra pilot screen.) However, the autopilot "clutch" was not engaging. From various terse bits of info on diverse web sites (certainly not from the manual) I learned that when the AP is engaged, a solenoid on the back side of the ram pushes a piston valve into place that locks the ram to the pump (and hence locks out the steering wheel.)
IMG_4416.jpeg

Something like this. But apparently not quite this because my equipment is twenty years old.
R4112-aO12-1.jpg

So I unloaded everything from the quarterberth cargo hold, opened up the access hatches, and did some calming yoga poses to prepare to investigate.

First checked electrical connections and inputs. All good... ish. Solenoid connections supply power when autopilot is engaged. Main 12VDC connections supply power (forward or reverse) when the pilot subsequently attempts to change course. The other connections are for the rudder position sensor, which we already established is working correctly.

AHA! The solenoid connections are only supplying 8.7 volts! Maybe a fault farther up the wiring! So I opened up the nav station and opened up the APC2 computer, to see what voltage it starts out with. Only to discover a sticker that reads: "Coil voltage factory set at 9V - sufficient for T1 and T2 rams." Well... not entirely willing to drop that line of inquiry yet, but it appears to be as per design. (WTF? Everything I've found so far states that it's supposed to be a 12VDC solenoid.)

So I crawled down there with the autopilot remote and observed what happens when the autopilot is turned on. When activated, as noted above, the voltage appears and the wheel is NOT locked out. So I am pretty much focused on the solenoid valve. I can touch, but can't see it.

Then, when a course change is input, voltage comes on to the hydraulic pump, which tries (and fails) to move the ram (because the solenoid is not closed). As the pump whines away, a drop of oil squeezes out around the ram shaft. So the seals are probably on the way out as well. By means of an extreme yoga lunge and possible spinal damage, I got my head in there and found no evidence of oil leakage in the dust below the ram. So I doubt that it has burped out all of its hydraulic fluid, though that is still a logical possibility. (i.e. if there were air instead of fluid in there where the "clutch" is supposed to go.)

I can feel the "clutch" but not see it. Holding the phone out as far as I can yields this image:
IMG_4406.jpeg


I think I've done everything I can with the unit in situ. So today's task is to extract the ram unit from the belly of the boat and get it out where I can look at it. After carefully noting and labeling all the wires in the terminal strip.

If this thread ends here, I probably got stuck down there and am slowly starving/freezing to death.
 

See Level

Working to overcome my inner peace
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Over there
If the solenoid is working it should become magnetic when active, if it does and isn't working it's stuck, if it doesn't become magnetic it has a dead coil or bad wire.
 

toddster

Super Anarchist
4,458
1,144
The Gorge
If the solenoid is working it should become magnetic when active, if it does and isn't working it's stuck, if it doesn't become magnetic it has a dead coil or bad wire.
Good test idea. I can't detect any external magnetization, holding a cheap metal tool against the case.

But now that I know what I'm looking for, (and maybe the wind is howling a little less) I can clearly hear and feel the snap of the piston moving in and out when it's switched on/off.

Starting to look more like a seals/fluid issue.
 

See Level

Working to overcome my inner peace
3,016
1,381
Over there
Shuttle valve is probably plugged or a o-ring failed, if you pull the unit you can open it up to see or take it to a hydraulic shop.
 

toddster

Super Anarchist
4,458
1,144
The Gorge
Update: waited all weekend for businesses to open but somehow failed to make contact with anyone on Monday.

This is one of those projects that takes a long time to figure out until the trick to removing it suddenly reveals itself. Couldn't unscrew the mounting bolts because some dipshit dipped them in silicone sealant during installation and they're at the limit of my arms reach. Removing the pins on the spindle didn't seem to do anything, until I discovered that then you can pull off two little plastic disks that keep the spindle in place et voila!

IMG_4426.jpeg

Retrieved the model & serial numbers (latter cleverly hidden on the bottom face between the mount and the cylinder so there is no possibility of reading it in situ.

Pushed the actuator rod in and out... oh yeah, there is air in there where there should be oil. Gurgling noises & sudden lack of resistance.

Maybe one could just top-off the fluid? (LMFAO). I mean, I still can't find anyplace where a lot of fluid obviously poured out. Though the quantity of air I seem to feel in the cylinder makes a slow leak hard to believe in.
The thing requires ISO 10 Hydraulic Fluid which takes some decoding. Not easy to find this stuff in the US, at least in small quantities. Google keeps trying to feed me SAE 10W which is equivalent to ISO 32. Some sources claim SAE 5W is equivalent but the actual labels say they're ISO 22. Finally, I find that "No 6 Spindle Oil" appears to be equivalent to ISO 10 and relatively small quantities can be purchased. Oddly enough, when you search for this, SailRite Sewing Machine Oil keeps coming up. It couldn't be that simple, could it? I have some on board! (No actual grade specification appears on the SailRite label or ad, but I sent an inquiry.) *sigh* Maybe if I can find a source for the seal kit, they will also have the fluid.

Which brings me to: Parts. This thing appears to be the same as the HyPro ML40, for which a seal kit is available. Though it looks a bit complex, with 28 pieces. Oh, and special tools. The "manual" is just this drawing.
ram repair.jpg

But maybe not really much worse than some of the lab equipment that I used to fix all the time.

Or a third possibility is maybe tracking down someone that I could just ship it off to for a rebuild.

Well, more information needed. But I really want this turned around quickly. It's a fairly critical item for me to single-hand this boat.
 

See Level

Working to overcome my inner peace
3,016
1,381
Over there
You could give these guys a call, I think they'll work on it. They do a lot of the high end yacht hydraulic repairs in Seattle.

Screenshot_20230206-180013~2.png
 

toddster

Super Anarchist
4,458
1,144
The Gorge
I have a similar unit in my garage if you think it will help. It was working when I pulled it off the boat. Also a bunch of H2000 components.

View attachment 573200
Thanks. That might be a useful thing to follow up if for some reason I'm unable to repair my current unit. ( I'm suspecting that making it work hard in freezing or near-freezing conditions pushed the old seals to their limit.)

I've contemplated upgrading everything to H5000, but my eyes keep bleeding over before I can come up with a grand total cost. The ram was the one component that I was sure I wouldn't have to change.
 

DavidRoss

New member
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0
I've had good luck using motorcycle fork oil which is 2.5wt. I did some research last year and that seemed to be the same as ISO10.
Did you decide to get the rebuild kit? I emailed the company to see where it's for sale State side as my ram has developed a leak as well.
 

toddster

Super Anarchist
4,458
1,144
The Gorge
The US distributor talked me into ordering a new ram. Raised the specter of the motor crapping out ("that comes next!") at sea. (But... can't you just carry spare brushes?) Basically refused to sell me the parts but offered dealer cost. It won't be a straight bolt-on replacement. I'll have to take the quadrant to a machine shop (since I no longer have a shop full of tools.) I'll try an oil fill to limp back to home port, but more likely a few long days of cold hand-steering.
 

DavidRoss

New member
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The US distributor talked me into ordering a new ram. Raised the specter of the motor crapping out ("that comes next!") at sea. (But... can't you just carry spare brushes?) Basically refused to sell me the parts but offered dealer cost. It won't be a straight bolt-on replacement. I'll have to take the quadrant to a machine shop (since I no longer have a shop full of tools.) I'll try an oil fill to limp back to home port, but more likely a few long days of cold hand-steering.
That sucks. They are good rams. They are just old enough that the orings are starting to fail.
I'll probably take it apart and order orings piecemeal.
I just re-built the motor last year. Nothing in there but brushes to go bad. Brushes were down to a nub but the commutator looked like new. Good for another 10 years with new orings and seals.

cheers
 

Beer fueled Mayhem

Anarchist
661
196
Ballard, WA
The US distributor talked me into ordering a new ram. Raised the specter of the motor crapping out ("that comes next!") at sea. (But... can't you just carry spare brushes?) Basically refused to sell me the parts but offered dealer cost. It won't be a straight bolt-on replacement. I'll have to take the quadrant to a machine shop (since I no longer have a shop full of tools.) I'll try an oil fill to limp back to home port, but more likely a few long days of cold hand-steering.
My buddy had the same thing. Same unit as yours. And you are right. The new one will have a different range. We didn't know that when we swapped them out and so, for now, he was a very limited port turn radius...
 

toddster

Super Anarchist
4,458
1,144
The Gorge
According to the spec sheet, the stroke range should be the same, but the base will have to be relocated 5/8" to starboard and the rod connection to the quadrant is different - will have to be re-drilled and tapped. Not something I can do reliably with hand tools.
 

Beer fueled Mayhem

Anarchist
661
196
Ballard, WA
Hmmmm. I think my buddy thought the same thing and we still had the problem.
Keep us posted. Maybe put the two side by side and compare before mounting. As my dad used to say, "you might be right..."
 

toddster

Super Anarchist
4,458
1,144
The Gorge
Received the new ram. It's going to have to wait until we return to home port for installation.

Meanwhile, I topped-off the old one with 2.5 wt. fork oil, burped all the air out of it as best I could and reinstalled. Seems to work. Can't see any obvious leaks, just operating it at the dock. Could last for an hour, could last for a year. Will put it to a longer test tomorrow.
 

toddster

Super Anarchist
4,458
1,144
The Gorge
The ram lasted another 54 engine hours or almost exactly one month. Ironically, it would have been exactly long enough to get back to home port where it will be replaced, except it turns out that the navigation locks at all Columbia and Snake River Dams are closed for annual maintenance. So I wasted those last few hours going up to Bonneville and then falling back to the previous anchorage. Denied!

Refilled it again, but the leak around the shaft seal is getting more obvious. Guess I'll hand steer unless absolutely necessary for the duration.

I actually did notice, while motoring up the river over the previous couple of days that all the big river tugs seemed to be tied up at their home docks. But somehow, the penny didn't drop. D'Oh!
 

DavidRoss

New member
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0
I would bet any good hydraulics shop can re-build that ram
I had a local shop replace my shaft seal and wiper for $100. They had never seen a ram like this and weren't interested in rebuilding it.
This time around, I opted to buy the full rebuild kit and sent the shaft out to be re-chromed as it was worn thru in places.
I'm taking photos and videos of the process and plan to make a rebuild video of the process as it's a dozen o-rings, ball bearings and little springs.
They are build so the bodies dont wear and the rebuild kit replaces every wearable part.

Great units.
 


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