Random Toad brake question: Why not use trailer brake controller???

[wamcneil]

So I was driving my new (to me) expedition the other day, with a factory trailer brake controller and it got me to thinking about toad brake systems. I was using the expedition to pull my grand cherokee toad at the time...

Electric trailer brake systems are a very mature, standardized and reliable technology, right? There must be literally millions of trailer brake controllers on the road in pickups and RVs. But I'd never come across a toad brake system that utilizes an electric trailer brake controller. Seems like toad brake manufacturers have invented a bunch of different ways to control the braking (some better than others...), but why not the electric trailer brake controller???

I did some searching and only found one toad brake system that uses a trailer brake controller on the RV, the Brake Buddy Stealth (edit: just read that this one ONLY works with the included brake controller, NOT a standard trailer brake controller). I'm not promoting the brake buddy stealth, BTW, their implementation is horrendously complex IMO, but that's a subject for another debate. I'm just talking about the use of a trailer brake controller on the RV end to control a toad brake. Why is this not a fairly common thing?

Seems to me like it would be pretty simple and reliable to use a trailer brake signal to control some kind of proportional electric actuator on the toad.  

Personally, I've got an air pressure-based system, which I think makes a lot of sense on an RV with air brakes, but it's no use when I'm pulling the toad with a pickup. If I had a similar system that used an electric actuator and trailer brake controller rather than air pressure, it would be much safer to have toad brakes when I'm pulling it with something less massive than the diesel pusher. I suppose that's an argument for the portable/inertial systems, but I want a system that does NOT have a mind of its own and is driven in direct response to how hard my foot is pressing on a brake pedal.

Thoughts? 

Walter

 

Edited June 14, 2023 by wamcneil

[RoadTripper2084]

Excellent question and one I also had when rigging my toad's braking system (Demco Stay-IN-Play DUO). After all, if I was towing a car on a dolly, I'd be using a brake controller, wouldn't I?

 

[Gene Y]

In our previous toad we had the Roadmaster Invisibrake which operates off of an electronic signal. Out of necessity we pulled it with our Armada. Using the same 7 pin trailer plug as our RV has we had braking on the toad same as when pulling with the RV

[wamcneil]

That’s a little different. 
“System connects to RV and engages car brakes when the RV brake lights illuminate.”

Apparently the invisibrake is a constant pressure type , rather than modulating brake pressure proportional to RV braking force. 
Im talking about using a trailer brake controller like is used to supply proportional braking signal to a trailer’s electric brakes.  

[wamcneil]

I've been doing some research on trailer brake controllers and they're apparently not as standard as I thought. Some are proportional and brake according to the tow vehicle's braking (like the Ford integrated controller in my expedition), but others are 'timed' and just send a fixed gain to the trailer brakes shortly after the vehicle brakes are applied.

Maybe that variability is why the toad brake systems don't want to use a trailer brake controller?

And maybe it's hard to set the gain correctly from way up front in a motorhome where you can't see or hear the toad's brakes locking up. Maybe the motorhome use-case would make the system less idiot resistant than towing a trailer with a pickup?

[birdshill123]

I still use the us gear  unified  tow brake system IMHO this is the best toad brake ever built it is proportional and uses the vacuum booster. New units are  not available but I bought one NOS system and a used system. I have enough spare parts to keep the system in working order for many years.  It is permanently installed on the toad  so only an umbilical cord yo connect.

Edited June 16, 2023 by birdshill123

[Tom Cherry]

13 minutes ago, birdshill123 said:

I still use the us gear  unified  tow brake system IMHO this is the best toad brake ever built it is proportional and uses the vacuum booster. New units are  not available but I bought one NOS system and a used system. I have enough spare parts to keep the system in working order for many years.  It is permanently installed on the toad  so only an umbilical cord yo connect.

Double DITTO and a Chorus of AMEN’s.  I installed one on my Hummer and loved it.  I would have installed it on my replacement, 2016, Yukon, but couldn’t find a practical or “socially acceptable”, to DW, spot to mount the solenoid.  One of the best and easiest to use out there.  I loved the single hookup where you didn’t need to out a pin or bleed brakes or move the seats.  

I chose the M&G for that reason and really love it.  You have one extra step, attach the QD air hose and TUG/PULL to make sure it is clicked and locked properly.

 

[wamcneil]

Interesting... Looks like the inventor of unified brake licensed his patent to another company that later dropped the product. Then he started SmartBrake with an improved version of the unified tow brake around 2013.

And SmartBrake used a standard trailer brake controller. 

Inventor Upgrades Unified Tow Brake System - RVBusiness - Breaking RV Industry News

Smart Brake - Adding Extra Stopping Power (motortrend.com)

But then looks like he disappeared again sometime about 2019 and smartbrakellc.com is gone.

I guess the market doesn't share my view that a trailer brake controller would be an elegant solution to toad braking.

 

Edited June 16, 2023 by wamcneil

[rcl285]

Having had several trailers and boats, as well as a motorhome towing a car and towing a boat at other times there are fundamental differences between a car and the other vehicles.  Trailers generally have electrically actuated brakes.  An electrical trailer controller can directly activate the brakes. With one trailer I had, there were mercury switched that modified the electrical drive of the brakes depending on the deceleration of the tow car.  There was no brake controller required in the car.  Electrical brake controllers can be designed to be stepped, inertially activated or proportionally driven.  After all, you are dealing with electrical circuits.  The boat trailer controllers I’ve had used a surge brake, which contained a hydraulic cylinder that used the force on the coupler to activate the brakes.  If the brakes on the towing vehicle are  activated, the force on the coupler is increased and that applies the surge brakes.  However, if you are towing a car, the car brakes are activated by somehow mechanically mimicking what happens when you step on the brake pedal.  This means that you must have a transducer that converts an electrical signal from the car to a mechanical force driving the brake pedal.  I’m sure that there are add on systems that exist, but the controller and the transducer must be compatible.  I’m pretty sure that there is not enough of a market to standardize on a universal transducer to work with all the electrical controllers in the marketplace. 

I have had the M&G air powered brake system on a Jeep Grand Cherokee and a Honda CRV for the last 20 years. The system inserts an air cylinder between the vacuum booster and the hydraulic master cylinder.  The air cylinder has a solid rod through it that allows the brake pedal to operate the brake when the air cylinder is not connected to an air source.  Since my Rambler has air brakes. All I have to do is connect an air line from the motorhome to the car being towed.  When I apply the motorhome brakes, the toad brakes are applied in proportion to the motorhome brakes.  No fancy transducer required to convert an electrical signal to a mechanical force, but I suspect that the air cylinder is custom for each car model towed.
 

my apologies for writing this, but my immediate thoughts when seeing the original post and repairs was that there was not a very good understanding of how the various braking systems available for towed vehicle.

Dick Lucas, 04 HR Imperial

[wamcneil]

Hmmm. Ok… Maybe the original post sounds like I’m proposing that a trailer brake controller could directly actuate a car’s hydraulic braking system???

I’m wondering why trailer brake controllers aren’t used to control an aftermarket toad brake system, which in turn actuates the toad’s hydraulic brakes. 

[Tom Cherry]

31 minutes ago, wamcneil said:

Hmmm. Ok… Maybe the original post sounds like I’m proposing that a trailer brake controller could directly actuate a car’s hydraulic braking system???

I’m wondering why trailer brake controllers aren’t used to control an aftermarket toad brake system, which in turn actuates the toad’s hydraulic brakes. 

My take.  The US Gear system actually had a “trailer brake” style or clone. There was a single solenoid that had a flex (lawnmower throttle cable style) cable that attached to the brake pedal bracket frame and MOVED the pedal.  It would work with conventional hydraulic brakes….or the Electro Hydraulic brakes found on the H3 Hummer or a few others.  My system on the Hummer did NOT have a vacuum canisters or boost…..it was an electric motor that activated the brakes and the motor generated enough power to work the normal hydraulic brakes.  These systems were few and far between….so, when my US Gear solenoid was turned on, there was a small Vacuum Generator used to assist the power brake canister OR it would also turn on the Motor for my Hummer.

THE REAL BUGABOO.  Most modern cars don’t like incoming power.  I had to add a diode in the Hummer’s electric motor circuit….as when i would use the vehicle without the brake umbilical even hooked up, there was enough of a feedback voltage to blow the brake fuse.  NOT GOOD as that killed the motor assist and you had to put both feet on the brake to work….same as if there was a leak or the engine vacuum (intake vacuum) line was disconnected and plugged to a conventional vacuum assisted power brakes…

There is no way to use a trailer brake on any “known” system as the trailer brake controller puts out a voltage or pulse controlled signal to solenoids.  It is probably cheaper to have an integrated controller in any modulated or pulse controlled system.  Calibration of a brake controller, as you have to adjust the sensitivity on, would be tricky

[wamcneil]

I think you’re probably right. It’s probably just cheaper and easier to design their own controllers rather than design around a trailer brake controller.
 

[RoadTripper2084]

17 hours ago, wamcneil said:

I think you’re probably right. It’s probably just cheaper and easier to design their own controllers rather than design around a trailer brake controller.
 

Yeah, plus the additional headache of trying to support a bunch of 3rd party brake controllers with their toad braking systems wouldn't be worth it either.