Steering Upgrade Ideas

Arcticelf

Arcticelf

Head BFH Operator at Gray Man Fab
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FreshSeaBass said:
https://www.steelsoldiers.com/threads/fail-proofing-full-hydro-steering.54804/page-4

Lots of talk about full-hydro on here. It sounds like unless you blew the pump, ram, hoses, and orbital all at once then you would still have some steering to get safely off the road in the event of a failure i.e. a hydraulic fluid leak somewhere. Not saying it for certain, but it seems like full hydro isn't as "unsafe" as some people claim it to be.
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Can it be made highway safe: absolutely.

Are the systems used in most crawlers or TTs highway safe: No.

Personally, I'm more concerned about the safety issues (lack of redundancy) than I am about the performance compromise of R&P or swing-arm steering boxed.

YMMV, but let's be real about the risk: if you loose fluid pressure in a hydro system you loose steering control. That's a ram gasket, a high-pressure side hose, the orbital valve or the PS pump. Leaks in the low-pressure side will cause problems eventually, but your pump will start making noise before you loose steering.

Adding a secondary ram system (what the military truck guys were discussing) is a very valid option, if you have room, which we don't.

Checking drag-links, alignment, tie rods, etc, should be part of your post trail; pre-highway routine while airing back up to make sure your mechanical links are safe.

If anyone wants a 2nd gen taco rack to use in prototyping a hydro-assist/power rack saver system let me know and I'll send you one that's collecting dust in my shop.
 
FreshSeaBass

FreshSeaBass

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Arcticelf said:
Can it be made highway safe: absolutely.

Are the systems used in most crawlers or TTs highway safe: No.
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YMMV, but let's be real about the risk: if you loose fluid pressure in a hydro system you loose steering control. That's a ram gasket, a high-pressure side hose, the orbital valve or the PS pump. Leaks in the low-pressure side will cause problems eventually, but your pump will start making noise before you loose steering....
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My big question and the reason I'm asking is due to some of my personal experience with hydraulic systems and the only personal experience I have had with hydro steering. We had a vehicle that was dead and not running but had hydro steer on it, so we tried to steer with it off and it would turn similarly to how our trucks are without power steering.

My understanding is that if you blew a seal and or sprung a leak then you would have some steering for a little while. If I am not mistaken, you would have to compromise the entire system at once to completely loose steering....?

Correct me if I am wrong. I appreciate the insights!
 
Arcticelf

Arcticelf

Head BFH Operator at Gray Man Fab
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FreshSeaBass said:
My big question and the reason I'm asking is due to some of my personal experience with hydraulic systems and the only personal experience I have had with hydro steering. We had a vehicle that was dead and not running but had hydro steer on it, so we tried to steer with it off and it would turn similarly to how our trucks are without power steering.

My understanding is that if you blew a seal and or sprung a leak then you would have some steering for a little while. If I am not mistaken, you would have to compromise the entire system at once to completely loose steering....?

Correct me if I am wrong. I appreciate the insights!
Click to expand...

If there is fluid going into the orbital valve I believe it will act as a really bad pump and let you move the ram, but that also depends on the design of the valve (beyond my scope of knowledge). If the leak is between the orbital and the rack: potentially SOL. If the leak is bad enough before the orbital, also SOL.

As a matter of risk management the question I'm asking is "how bad would the effect of the failure be?" not "what's the probability of failure?" And I'm comparing that answer to the failure modes of the other types of steering system.

I've lost power steering enough times, in enough different vehicles, that a mechanical linkage is a hard requirement for me. There are other ways to skin that cat, and also other risk profiles that are sane to accept. As we've been talking about this I'm increasingly convinced that modern hydro-steer can be roadworthy, with the caveat that any leaks in the system are a "hard-down" fault that must be fixed before driving at any speed on public roads. Similar to the way we treat ball-joint or drag-link failure.
 
FreshSeaBass

FreshSeaBass

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Arcticelf said:
If there is fluid going into the orbital valve I believe it will act as a really bad pump and let you move the ram, but that also depends on the design of the valve (beyond my scope of knowledge). If the leak is between the orbital and the rack: potentially SOL. If the leak is bad enough before the orbital, also SOL.

As a matter of risk management the question I'm asking is "how bad would the effect of the failure be?" not "what's the probability of failure?" And I'm comparing that answer to the failure modes of the other types of steering system.

I've lost power steering enough times, in enough different vehicles, that a mechanical linkage is a hard requirement for me. There are other ways to skin that cat, and also other risk profiles that are sane to accept. As we've been talking about this I'm increasingly convinced that modern hydro-steer can be roadworthy, with the caveat that any leaks in the system are a "hard-down" fault that must be fixed before driving at any speed on public roads. Similar to the way we treat ball-joint or drag-link failure.
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Roger that. If you go with a load-reactive orbital and get one that is dual displacement it will do exactly what you mentioned. It will actually pump fluid because it acts as an impeller of sorts. In the event that a hose or fitting leaks, you will have enough pressure to steer momentarily unless of course you have a dual hose/fitting failure. Not saying it's not possible, but it seems highly unlikely. If you lose both hoses due to a leak, you will at least have time to maneuver off the road.

Without a doubt frequent checks are necessary on all systems and I think that it will allow you to really determine what the failure point is before a catastrophic failure.
 
Arcticelf

Arcticelf

Head BFH Operator at Gray Man Fab
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FreshSeaBass said:
Roger that. If you go with a load-reactive orbital and get one that is dual displacement it will do exactly what you mentioned. It will actually pump fluid because it acts as an impeller of sorts. In the event that a hose or fitting leaks, you will have enough pressure to steer momentarily unless of course you have a dual hose/fitting failure. Not saying it's not possible, but it seems highly unlikely. If you lose both hoses due to a leak, you will at least have time to maneuver off the road.

Without a doubt frequent checks are necessary on all systems and I think that it will allow you to really determine what the failure point is before a catastrophic failure.
Click to expand...

Maintenance and inspection intervals are key.

So is understanding your reliability requirements. I want to be able to drive home (100s of highway miles) with a power steering failure. That is not everyone's requirement.
 
FreshSeaBass

FreshSeaBass

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Arcticelf said:
Maintenance and inspection intervals are key.

So is understanding your reliability requirements. I want to be able to drive home (100s of highway miles) with a power steering failure. That is not everyone's requirement.
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Totally, under any sort of situation where that could be an issue, I want to be able to have a mechanical fail-safe should there be a failure like that. With modern re-useable hydraulic JIC fittings, hoses, and basic tools, a hydraulic leak can be completely repaired and you can build new lines out in the field. I often look to CAT machinery, military equipment, and heavy industrial farming equipment and think that if it works well enough for them to be out in the field far away from help, then surely theres more to it.



I have a feeling we will see some of the first Toyota IFS full-hydro soon.
 
Stairgod

Stairgod

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FreshSeaBass said:
My big question and the reason I'm asking is due to some of my personal experience with hydraulic systems and the only personal experience I have had with hydro steering. We had a vehicle that was dead and not running but had hydro steer on it, so we tried to steer with it off and it would turn similarly to how our trucks are without power steering.

My understanding is that if you blew a seal and or sprung a leak then you would have some steering for a little while. If I am not mistaken, you would have to compromise the entire system at once to completely loose steering....?

Correct me if I am wrong. I appreciate the insights!
Click to expand...
Mechanical steering being a fail safe is dependent on many factors.
Blew the pressure hose on my dually. Lost both steering and brakes at the same time. Stopping or turning that big fucker was nigh impossible without hydraulic assistance. Got it stopped halfway into someone's yard because I was mid turn and only doing 20 when the line blew.
 
FreshSeaBass

FreshSeaBass

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Stairgod said:
Mechanical steering being a fail safe is dependent on many factors.
Blew the pressure hose on my dually. Lost both steering and brakes at the same time. Stopping or turning that big fucker was nigh impossible without hydraulic assistance. Got it stopped halfway into someone's yard because I was mid turn and only doing 20 when the line blew.
Click to expand...

This is the kind of insight I'm looking for! Considering my brakes wont be a part of the system, it seems like a non issue. What was the cause of failure? That seems like literally the worst luck on earth.
 
4runner DOA

4runner DOA

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Arcticelf said:
Yeah, I've seen those. I wonder how much work actually went into that rack? The Marlin Crawler IFS is stupid, and they only sell the rack as part of their LT kit (I assume because of bump-steer and fitment issues).
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I think @Airdog was looking at it, can't remember if he figured out how much work it would actually take.
 
Stairgod

Stairgod

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FreshSeaBass said:
This is the kind of insight I'm looking for! Considering my brakes wont be a part of the system, it seems like a non issue. What was the cause of failure? That seems like literally the worst luck on earth.
Click to expand...
Hose was rubbing against the steering column. Over 300k miles it rubbed a hole in it. Original factory line and routing(read as not my fault,lol)
 
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