Anti-Lock Brakes for Travel Trailers

[slowmover]

This is not a thread about tow vehicles. Or inadequate brake maintenance. Or cheaply done connections, if you please:

Some of you may already be familiar with Tuson RV Brakes via buz the past year on:

DIRECLINK

I was wandering around the Net tonight and came across reference to an installation of disc brakes and the DIRECLINK setup on a canned ham restoration:

Mark Polk RV Education, Episode #17

(brake install first, actuator & lines at 11:30 thru 20:00, and cab controller a few minutes later; yes, his hardware install could be better, as could location-mount of actuator)

TUSONRVBRAKES YouTube Channel

I've been calling the addition of a state-of-the-art brake controller to a TT converted to disc brakes (along with a VPP hitch) The Gold Standard for about a year or so.

What was lacking was anti-lock capability for the trailer. While I don't yet see the ABS module for sale yet, the video's are a step in that direction.

I did send for the brochure offered by TUSON and I recommend it heartily, without regard to experience or skill level in brakes, for it is comprehensive and well-written. A nice reference should one wish to think through a brake system while making notes preparatory to an upgrade (not a sales brochure, per se). And excellent for the newbie parked next door.

Having flat-spotted TT tires in the dim, dark past, I'm anxious that the next TT for us have this kind of system. The thought of old, high-crowned, patched asphalt highway and rain is always enough to be worrisome. Locked brakes cause the vehicle affected to travel faster, not slower, on wet surfaces. (Yes, we can performance test our systems on a variety of surfaces, and under a variety of conditions, to note optimum brake controller settings. Still, that's at best a half-step).

Now, I realize there are those who think this style of actuator is slow to respond, and there are those for whom drum brakes and bias-ply tires are adequate according to them. I didn't start this thread for that discussion as there are other threads already containing these questions (although links to them would be welcomed).

Nevertheless, I'd recommend a read through the materials online and those available by request. If it is not the offerings of this company then it is hopefully only a matter of time before we can have the same type of braking performance as with our TV's: 4-wheel disc/antilock. What is on offer is sophisticated, and impressive.

What examples can be found of those who have installed them -- or RV companies offering them -- I haven't yet found.

My experience with trailer anti-lock is confined to tractor-trailer combinations. Little in life for an ordinary man can be as exciting as a 53' 50,000-lb trailer starting to come around. I've been happy to have pretty well have driven only antilock-brake trailers. Once was enough (and no jack-knife occurred, but it was close), and I never want to have something similar upset the "lane-centeredness" of my TT due to braking or undue steering inputs.

ABS for TT's is long overdue. Best hitch, best brakes, and best brake control.

Perhaps someone is familiar with what is available overseas, as America gave up the idea of being a leader in vehicle and road safety some while back. I've always been irked that a TT parking brake is required in places like New Zealand, for instance. But not here. Pride aside, it would be good to know,

and,

make this thread more than just about the offerings of one company, about anti-lock in general.

IIRC, the NHTSA found that anti-lock on passenger vehicles hadn't proved out the way it was hoped. Sounded rather like Jevon's Paradox to me. I'm obviously in favor, and hoping to learn more from others on this.

Thanks

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[Skater]

I think it's a good idea. I used to think anti-lock wasn't much help, but then I got into an accident where I locked up the front wheels. After it was over, I noticed that my front wheels were pointed left, trying to avoid the accident, and had lock-up not occurred I might've avoided the accident entirely. Also, I flat spotted two brand new tires, to add insult to injury.

I think for trailers it's an excellent idea for the reasons you state. Thinking about current systems, not completely redesigning it, I think a new, secondary brake controller mounted in the camper simply needs feedback about whether the wheels have locked or not, then it can release the brakes and re-engage, but back off this time; then repeat as necessary if the wheels lock again. I realize TT brakes are probably slower to engage/disengage, so it might not work as well. If there's a way to detect that the wheels are about to lock, so much the better.

Detecting whether a wheel has locked doesn't seem that hard to me; a sensor on the hub or something. The hardest part would be the logic in the new brake controller.

Of course, if someone were to completely redesign the brake systems, there are probably even better ways to do it. I was thinking from a retrofit point of view. For example, if the tow vehicle's antilock system could control all brakes attached to the vehicle...something along those lines...that'd be good.

[slowmover]

There is some discussion at present (May 10, 2012) on another thread in re the DirecLink Brake Controller.

[fltlevel510]

Have a friend with a 2011 28' Flying Cloud that has Airstream factory installed anti lock brakes. The installation includes Kodiak brake system with the DirectLink controller. He did say cost is somewhat high.

[slowmover]

For clarity's sake: there are two [2] versions of the DIRECLINK controller at present. The DIRECLINK ABS module is separate altogether from those two.

So, this man has both the DIRECLINK controller and the DIRECLINK ABS module present (along with Airstream-installed KODIAK disc brakes)?

It would be great to hear from him if that is so, and if he has put them to the test in any fashion.

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[C5Don]

DirecLink brake controller can do electric or electrohydraulic like any other "brake controller".

The Trailer Actuator Controller comes in two versions. One supports the optional ABS module, the other does not. I think the one that supports ABS is gold in color.

I got beat up in brake controller topic for not telling all, but will carefully try to say what I can say. The ABS system monitors each disc brake rotor and individually controls each disc brake caliper. Unless you are on ice or something, if you watch the videos you will note the wheels never really stop. They progressively slow down until the ramp back up and repeat.

I can't tell you all the physics involved, but as odd as it sounds, a fully loaded trailer will stop faster than an empty one! Why? There is more weight on the tires and the grip more than no weight. In effect there is a point in trailer weight where it will stop the TV and TT faster than the TV by itself!

On vehicles stopping in a longer distance with ABS then not, you are correct. I don't know why they do that, to be honest. All I can think of is it must be to maintain control of the vehicle. I have no idea why they need to do the violent jerking, as even ABS could be done smoothly. Since people don't think ABS is working if it doesn't jerk some, trailer ABS also provides some oscillation, but not violent.

In the ABS system you can actually turn ABS on or off if you want to. You can do this to compare stopping distances either way, but remember, with ABS turned off you will likely flat spot your tires, so if you do this, be careful. The ABS system and the actuator controller run all kinds of diagnostics. It will tell you if you loose a sensor, or more likely, something from the road knocks the sensor away from the wheel. All you generally need to do is then push it back down close to the pulse wheel. Also detects shorts and opens in the "wheel control solenoids" and such. In effect, they want to make it possible for you to diagnose the majority of fault that can occur due to poor wiring, someone doing a poor install and moisture getting in enclosure and so on. This stuff is all sent to the DirecLink Brake Controllers Command Module for the user to see. Fault screens will pop up every few seconds when a fault is detected.

Hope this helps some.

[slowmover]

C5, you be the galaxy of info, here . . thanks!

[TouringDan]

Rednax

Thanks for starting this thread. I have been driving cars with 4 wheel disc brakes and abs for 18 years now and we all know there is a huge difference between the stopping capability of drum brakes without abs and disc brakes with abs. This is why it is so important to be able to get disc brakes with abs on a trailer. Airstream being the best tt out there, I believe that abs disc brakes should be standard on all Airstream new trailers. I know that reliability is some concern, but if the disc brakes were standard, the reliability issues would get solved very quickly I believe.

fltlevel

Sure would be nice to have some photos of your friend's setup. I am still confused about what components are required to make this work. Is it just the DL abs brake controller plus the trailer disc brake system or is there abs trailer hardware also needed?

Dan

[C5Don]

TouringDan: The trailer ABS system consists of the following:

A DL Brake controller that gathers vehicle data over OBDII networks.

A Trailer Actuator Controller (gold version) that is "ABS Capable". The Trailer Actuator controller has a pump and modulating valves that control the flow of hydraulic pressure to the disc brakes.

An ABS Controller module, that connects to the Trailer Actuator Controller via a CAN network to "share necessary informaiton" to perform trailer braking, among other things. This module also connects to the wheel rotation sensors, one for each wheel. This is what "closes the loop" reative to knowing wheel rotation. The ABS module also controls some valves, that go in between the Trailer Actuator Controller output pressure and each brake caliper. These valves are used to individually control the braking of each wheel, among other stuff.

So there are two versions of the the Trailer Actuator Controller, one with the ABS hardware and electronics, and one without.

On other topic areas on brake controllers, can you run trailer abs control without a DL brake controller and the vehicle information, sure, just can't do as good of a job.

[slowmover]

A post on WOODALLS alerted me to this:

Al-KO Electronic Stability Control

which will at some point be available for retrofit on US travel trailers. Brakes are applied to keep TT in line behind the TV.

See link for more.


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[TouringDan]

Rednax

Thanks for posting. It is good to see another player providing ABS and now planning on developing stability control for trailers. Competition is good for all trailer owners.

Dan

[Skater]

Oh, cool - I didn't realize this thread had been resurrected, nor that there were already options available. Thanks for the updates, everyone.

Originally Posted by C5Don

I can't tell you all the physics involved, but as odd as it sounds, a fully loaded trailer will stop faster than an empty one! Why? There is more weight on the tires and the grip more than no weight. In effect there is a point in trailer weight where it will stop the TV and TT faster than the TV by itself!

This makes total sense to me - ever tow an empty tow dolly with electric brakes? I have! When those brakes activate, even lightly, the wheels lock up and the dolly goes bouncing. I always disconnected the brake controller when the dolly was empty.

[slowmover]

Finally, nearly two years after reading about this possibility I've come across an article describing the installation and testing of the TUSON (Direclink) TT Anti-Lock Brake Module.

By Kent Sundling, of MrTrailer:

"Tuson has ABS Trailer Brakes for fast smooth safer stops - - DirecLink trailer brake controller networks with trucks computer for faster braking and diagnosis

I especially like this quote:

" . . When using the trailer brakes only, the trailer brakes have to stop the truck and trailer (20,000 lbs) at a predetermined deceleration rate. This is how trailer brakes are tested in Europe."

Ahh, yes, . . civilization. The First World. Good to hear how it's done where reason is balanced against profit.


So have at it, boys. We're finally in the 21st Century!!

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[jdalrymple]

My god, I had no idea towing a trailer was so deadly..

Thats it. I am parking mine until I can move to Europe.

[dznf0g]

Almost maks me wish my actuator would finally fail, so I could justify the ABS and actuator!

[Wayward]

Originally Posted by REDNAX

"Tuson has ABS Trailer Brakes for fast smooth safer stops - - DirecLink trailer brake controller networks with trucks computer for faster braking and diagnosis

I especially like this quote:

" . . When using the trailer brakes only, the trailer brakes have to stop the truck and trailer (20,000 lbs) at a predetermined deceleration rate. This is how trailer brakes are tested in Europe."

Ahh, yes, . . civilization. The First World. Good to hear how it's done where reason is balanced against profit.

So have at it, boys. We're finally in the 21st Century!!.

Any typical braking system installed on a trailer is capable of stopping the combined rig "at a predetermined rate" on its own. Once the engineers move testing from the "bench" to the track, isolating the tow vehicle's braking system from the trailer's braking system would naturally be one of their tests.

I would not draw any socio-economic conclusions from it, that the trailer system alone is designed to operate continuously, or even safely, in such a configuration. It is simply describing a testing methodology for their design parameters.

I have been hauling heavy trailers my whole life and still would not buy this. But free market technology always drives down costs and results in better products. It is awesome that companies like Tuson can create a profitable business making ABS and disc brake technology available. Maybe, as they refine the technology, one day Airstream will offer a $5K option for it. Then the technology/cost curve will drop further making it standard equipment.

On the other hand I damn sure hope some Tuson or supplier lobbyist does not bribe the NHTSA politco's to mandate this technology and force Airstream to add another 5 grand to the price of a travel trailer for something I do not want or need.

My run of the mill American 3/4 ton pickup has sophisticated braking, sway control, engine and transmission control software integrated with the trailer connection and brake controller. It is a very sophisticated powerful tow package capable of hauling, stabilizing and stopping the whole rig with or without trailer brakes. Eat your heart out Europe!

[vswingfield]

Interesting, but I noticed that "The ActuLink ABS Module has 4 unique multi-valve channels controlled by the high speed digital network."


"Triple Axle - No Problem

The ActuLink ABS Module links the hydraulic channel of the center axle brake to either the brake in front of, or behind it depending on the type of suspension. This allows the system to be used on triple axle towables."

I would say that they are not quite there for triple axles.

[C5Don]

Like Wayward said its a market volutme issue. Using a bigger pump, more valves is not a tecnical issue but a return on investment issue. Adding two more channels, for two more sensors, and control for two more modulating valves requires new board layout, new packaging, some fimrware changes in both ABS module and hydraulic module as well as testing, manufacturing build changes and so on. Then likely a "bigger pump" due to volume, not pressure, as I recall. Thus more engineering and manufacturing costs. None of this is a technical problem, but how many units do yo need to sell before; 1) you pay back the development expenses and 2) actually get a return on your investment. If the return is there it will be done. This requries demand, and thus customer demand. You are 100% correct about volume, as that means evrything to manufactured cost, and thus price. For example, I am completing a tank gauge as we speak, also talks one network to all this other stuff. I "finished it" a while ago, but when I summed up the "final design" and "vinal manufactured cost" I was a bit high relative to what I thought the maket would be "willing to pay" for a quality gauging system OR I would have to cut the profit per unit and take MUCH longer to pay back the development expense. In this case I "bit the bullet twice" to reduce cost and should have it done shortly. SInce this is an RTOS product I am "paying myself" where if I was doing the product for others, due to my "development expense" they would likely be "shipping it right now" and would reduce cost later. So bottom line is "volume is king" to reducing costs and to be accurate "nothing else affects price more than volume". Such is the life of the "product supplier" side of the equation. Relative to the four valve system for triple axles, as stated, the proper axle selection for the two controlled axles has, I am told, worked out just fine. I am certain any personal experience, positive ro negative, would be appreciated by those at Tuson. Oh, by the way, I believe in Europe you are not allowed to have "manual control" and although I may be wrong, I also beliieve you are not allowed to adjust anything, like "scaling / boost". I don't personally know why they have these rules, they just do. Such is the life in "big brother" land.

[Wayward]

Originally Posted by C5Don

I believe in Europe you are not allowed to have "manual control" and although I may be wrong, I also beliieve you are not allowed to adjust anything, like "scaling / boost". I don't personally know why they have these rules, they just do. Such is the life in "big brother" land.

Bureaucrats beget regulations, which beget more bureaucrats. Here is where "good intentions" always lead when entrusted to government bureacrats.........."Roadworthiness Testing". Sounds good - right?

The European Commission is outlawing the use of any modifications and non-original components to motor vehicles and their trailers:

The draft of the new Directive has implications for all motorists, not just historic vehicle owners. Amongst other things, the draft includes requirements to test all trailers... and requires tests to make reference to a vehicle’s original ‘technical characteristics’.

[slowmover]

No, the pendulum can swing both ways. Deaths, injuries and property damage can be put in decline with changes in all aspects of law, mandates, etc, and vehicle specification is just one approach.

Searching a cost:benefit analysis is the first start, thus the reason for this thread: Anyone who has experienced a trailer jack-knife is going to be interested, one would think, in improvements to avoid that scenario.

That improved straight-line braking is also part of the mix is a distinct secondary benefit.

That some don't want this sort of improvement is entirely beside the point, nor is it in accord with proven results.

The "article" I linked above is as much about hydraulic disc brakes over electro-mechanical drums . . anti-lock is icing on the cake. A final, but necessary piece.

Now, as to triple axles (tridem), one might also note that the rear of the trailer "lifts" under heavy braking; that the rearmost axle becomes unloaded -- as noted elsewhere on this site; a quote by Andrew T of Can Am RV -- and this "may" (per C5Dons comment on TUSON experience to date) account for the efficacy of tandem over tridem "programming" [word used as shortcut].

It may be that, at present, (short of user data as noted) a tridem axle trailer will act no better than a tandem in brake performance testing overall in regards ABS systems due to load decreases FF to RR even though more "rubber & brake" is present on the tridem.


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