Need advice on Hydraulic Autopilot install

[FranklinGray]

My 1985 Whitby 55 which weights currently 60,000 (loaded) needs a new autopilot. I was very happy with my Raymarine on my Hunter 376 so I bought a Type 3 Hydraulic ram drive with with EV core pack.

The old B&G, which must me like 30 years old, had a hydraulic ram drive with the pump attached to the drive (on the side). The new systems for this size of boat seem to have the pump disconnected but attached by hoses. This is where I am having troubles.

The Raymarine manual and customer support both say that the pump must be mounted horizontally right side up and at least the same level as the drive. Considering one of the hoses comes out the top of the pump and that there is only 1/4 inch between the top of the drive and the bed floor, it is impossible to do so on my boat without a total reconstruction of the aft cabin which would also reduce headroom that is very limited already. They say that it could get air in the system and cause a vaper lock.

So, have any of you ever had a vaper lock in your autopilot? Customer Support seems to say it happens a lot. What is the effect? How do you deal with it?

[pcmm]

If the ram and the pump are now separate, whats to stop you installing the pump in a different area that does have the required space? just more fluid in the lines, still the same volume of fluid that is moving the cylinder back and forth.

[FranklinGray]

Originally Posted by pcmm

If the ram and the pump are now separate, whats to stop you installing the pump in a different area that does have the required space? just more fluid in the lines, still the same volume of fluid that is moving the cylinder back and forth.

Not without having the hoses drop below the drive unit. Wouldn't that also cause the air to stay in the drive unit instead of bubbling up to the reservoir?

[pcmm]

Originally Posted by FranklinGray

Not without having the hoses drop below the drive unit. Wouldn't that also cause the air to stay in the drive unit instead of bubbling up to the reservoir?

Shouldn't cause issues as long as you've bleed the system. Lots of hydraulic systems have lines below the cylinder. My steering from the factory has about 5ft of hose that is lower than the cylinder. The whole system is lower than the helm, including the reservoir. Even my AP pump has hoses that dip below the level of the cylinder.

[FranklinGray]

Yeah, if I keep all air out of it, then there is no reason to worry about the pump being below the drive either. I am assuming Raymarine has these install requirements because air does get into the system somehow. Don't know if it's because users are not replacing leaking hoses or the seal wears out.

I think I'm just going to mount the pump on the hull floor for now and then worry about it later if I start getting a mushy unresponsive autopilot.

[Scrimshaw4]

I second pcmm's comment about bleeding the system. The bleeding may use up a lot of fluid but it's key to the system working. One person at the helm, the other at the ram. Work the helm and autopilot and continue to add fluid. Follow the manufacturer's bleed instructions and you'll get the air out. The fluid pushes the air out. You'll know it's bled when a steady stream of fluid comes out of both bleed ports on the cylinder.

[lifeofreilly57]

Go to your local hydraulic hose supplier, get right angle fittings for the hoses coming out the top. This will allow you to place the pump pretty much level with the system, depending on the space available. Hoses running above the cylinder can be a bugger to get air out of, the fill tank aso needs to be mounted above the highest point of the system to allow air bubbles to work themselves out. This isn't a closed system per se, like a backhoe or some hydraulic devices.
I replaced my raymarine system with a B&G Type III setup after having too many issues with the original Raymarine.
My boat is a center cockpit, so space under the master queen bed is limited, I ended up having to remove the entire support system for the steering quadrant, the frame that supports all the pulleys. it's aluminum and needed to be modified to mount the new system.
These systems bleed by passing the hydraulic fluid past a low pressure port tied to the fill tank, if the hoses loop over the height of the pump it'll be a royal pain to bleed. Putting the fill tank at east 18" higher than the pump is a good idea.
If the hoses supplied are too short for your installation visit a hydraulic hose supplier, I'm sure they could supply longer hoses to fit your installation needs.
Any air in the system will cause the response to be sluggish and hunt constantly, this isn't good for the pump or the system, especially if the pump cavitates too much and turns the oil to foam, air is easily compressed, hydraulic fluid isn't.
I've installed quadrant driven systems on several boats, worked with hydraulics in industrial applications and on tractors and cranes. They're not all the same, they have their own particular setup.

[FranklinGray]

Originally Posted by lifeofreilly57

Go to your local hydraulic hose supplier, get right angle fittings for the hoses coming out the top. This will allow you to place the pump pretty much level with the system, depending on the space available.

Now why didn't I think of that. That hose sticking up out of the pump with the other two hoses sideways was driving me nuts.

Originally Posted by lifeofreilly57

This isn't a closed system per se, like a backhoe or some hydraulic devices.

I think this is where I was getting lost. It has 3 hoses and I have only seen 1 or 2 hose systems before.

Originally Posted by lifeofreilly57

I replaced my raymarine system with a B&G Type III setup after having too many issues with the original Raymarine.

Dare I ask what issues you had?

Originally Posted by lifeofreilly57

These systems bleed by passing the hydraulic fluid past a low pressure port tied to the fill tank, if the hoses loop over the height of the pump it'll be a royal pain to bleed. Putting the fill tank at east 18" higher than the pump is a good idea.

It already seems like a royal pain to bleed. These are the steps the manual states. Nothing like anything I have ever bleed before:

1) turn tap on
2) pull rod all the way in
3) fill reservoir
4) 'slacken the pipes' -- now that is worded weird. I assume they mean loosen the fittings on the hoses to the ram.
5) re-tighten the hoses once oil comes out
6) energise the cylinder solenoid...I assume they mean turn the autopilot on.
6) push rod all the way out and check fluid level in reservoir
7) pull rod back in and keep doing that until no more air coming up in reservoir.
8) de-energise the solenoid -- turn it off?
9) turn on autopilot and change course to make pump run in both directions.
10) top off reservoir.

this is just wacko. Now I understand why they say the pump needs to be at least level with the drive. They don't have a good way to bleed the system.

[FranklinGray]

I think I am understanding their design a bit better. Once it is bleed and working properly, the system is designed to be self bleeding. So even if you have a leaky connection, as long as there is fluid in the reservoir it should work (mostly).

After another look, even with a right angle elbow, the hose connections to the pump will still be 2 inches lower than the hose connections to the drive (pump has the connections on the side but the drive has them on the top). I assume that would disable the self bleeding design as air doesn't go up down hill.

The system came all primed up and ready to go minus the reservoir so I was not wanting to do this, but it looks like I will have to disconnect the pump, drain the fluid, drill holes in my bed base and run the hoses into a locker beside the bed and mount it there with the reservoir being in another locker higher up. That means I really gotta bleed this thing good when done and I'm sure I'll get fluid everywhere.

Well, at least I have a plan now.

[FranklinGray]

I wonder if that 3rd hose is a over-pressure safety return hose.

[lifeofreilly57]

The issues I had with Raymarine had to do with the cylinder, it needed new seals, they wouldn't supply them and told me I needed to buy the cylinder and pump together, they're not sold separately, period. Take it or leave it. I had other issues with their tech support previously, with some good advice, some not so good, on a different system.
Through several boats I've had systems from several different suppliers, and so far B&G has been the easiest to install and set up. Garmin's human interface isn't as user friendly as others, tech support mixed. Raymarine charges premium prices and likes to use their proprietary communication backbone which can be a pain, B&G uses NMEA 2000 for their comms, which makes integrating it with third party devices easier. Like AIS, radios, etc.
Realistically, bleeding a pump is pretty straight forward, crack the fitting at the pump, get air out, crack the fitting at the cylinder and bleed air, run it a bit, let it sit, then repeat. Cycling the cylinder is also a good way to get the air out once you've gotten most of the air out, but may require additional bleeding at the fitting. Cycling the solenoid makes sense, it's what frees the hydraulic system when your hand steering, otherwise you'd be fighting the cylinder.
It takes a bit of patience, but isn't too complicated.
I had to do it again once when a factory sealed fitting loosened and bled out the hydraulic fluid while transiting the Mona passage, I had to hand steer the next 20 hours til I could drop anchor and fix it. So check the factory installed fittings while your at it, might have been the last one installed prior to the assemblers coffee break.
On my backhoe after rebuilding a cylinder you just hook it up and cycle the cylinder 8 or 9 times, the rams extend all the way to the end of the cylinder and squeeze out air pretty well, the large reservior allows the foaming fluid to expel air bubbles, the tank on your system is much smaller. The hydraulic pump also has a pressure relief on it which recirculates the fluid to the tank which also helps bleed air, auto pilot systems don't.

[lifeofreilly57]

Depending on where you are, Pirtech is an easy hydraulic supplier to work with, they usually have good service, they'll even come to you (for a price) if needed and make up hoses on site. They're a national supplier with franchises in many locations, I've also used independent suppliers, but they are usually more focused either on the construction industry or the manufacturing sector. Depends on your location.
Good Luck, hope it goes smoothly. Use lots of rags.

[fredNerk]

Originally Posted by lifeofreilly57

The issues I had with Raymarine had to do with the cylinder, it needed new seals, they wouldn't supply them and told me I needed to buy the cylinder and pump together, they're not sold separately, period. Take it or leave it.

None of the Hydraulic components are made by Raymarine. This is a prime example of the Dealer trying to lead you into his "Walled Garden"
You can obtain all the Hydraulics from the actual manufacturer in the UK. They are most helpfull and very responsive along with being reasonably priced.



If you look on the pump end of the motor drive you will see a number. Search on that number. If you dont get a result. PM me and I will give you the Company and contact name.



Fred

[Brendan]

I installed a HyDrive hydraulic steering system on my pilot house yacht for the inside helm position. This included a pump installed in the engine room and copper pipes to the hydraulic cylinder at the steering quadrant. Copper pipes run below both electric pump and cylinder. I used some custom made hoses from a shop in Annapolis and, as long as the system is properly bled (not easy to do, especially single-handed), it is bomb proof. Controlled by a Raymarine autopilot. HyDrive is the same system they use on the UK's Lifeboats.

[pbmaise]

The main issue I have had is a crewmember hand steering the vessel when in automatic mode. This caused large amounts of hydraulic fluid to leak from my system. The hand steering is sometimes necessary in an emergency and I don't fret about crew members who can't be trained to take it out of automatic mode.

This situation has caused me to bring a lot of spare hydraulic fluid and I learned to buy the cheapest. In fact, I learned I could get by using cheap ATF instead.

My vessel also would lose its fluid during rough conditions when steering was difficult.

I learned to hand steer her during those conditions.