Smart Brake Auxiliary Braking System
Adding Some Whoa to Your Go
Article Date: June, 2013
A supplemental braking system is a must for any motorhome owner who tows another vehicle. The additional safety
in reduced braking distance can make the difference between just missing whatever pulled out in front of you and having to take your RV
to the body shop. In addition, should the tow bar fail or the towed vehicle ever become disconnected from the motorhome, the breakaway
protection will apply the towed vehicle's brakes, preventing a dangerous runaway vehicle that could potentially harm others.
Various supplemental braking systems are offered. Simple portable boxes are available as well as permanent-mount
systems that utilize various methods to provide supplemental braking as needed. One particularly impressive unit is the Smart Brake. The
Smart Brake is made by Ron Chesnut, the original inventor of the Unified Tow Brake sold by US Gear and offers a number of upgrades and
enhancements that really help set this braking system apart from the rest.
How It Works
The Smart Brake is an electric unit that can be used on gasoline- or diesel-powered motorhomes. A Smart Brain
module is installed on the vehicle; most generally this is someplace in the engine compartment, but it is weatherproof and can be
installed behind a front bumper or other convenient location, as well. A mechanical cable and housing runs from the Smart Brain through
the towed vehicle's floorboard and connects to the upper arm of the brake pedal. This cable pulls and applies the brakes as needed and
is left in place so that it does not affect regular driving of the towed vehicle. A small vacuum pump is also mounted in the engine
compartment to supply vacuum to the brake system vacuum booster so that the power brakes are active when towing.
A seven-pin RV-style umbilical cord connects a socket at the front of the towed vehicle with the receptacle at
the rear of the motorhome. A breakout connection is supplied in the Smart Brain module to feed the tail, turn, and stop lights of the
towed vehicle and will receive braking information from the motorhome. A breakaway switch is mounted on the front of the towed vehicle,
and a safety cable connects to the RV to apply the brakes should a breakaway situation occur.
The Smart Brain module is equipped with plug-in wiring harness connections and the controller cable that connects
to the brake pedal.
The Smart Brake is equipped with a vacuum pump to keep the vehicle's power brake vacuum booster charged while towing.
Most electrically operated supplemental braking systems use some sort of inertia sensor or accelerometer to sense
how much braking is required. This isn't the most accurate method because it can't compensate for downgrades or engine brakes when it's
not desired to apply the brakes on the towed vehicle. The Smart Brake doesn't use inertia sensors. Instead, it utilizes the signal from
a standard trailer brake controller mounted in the motor-home. Most motorhomes are prewired for electric trailer brakes so it's an easy
task to add the trailer brake controller of your choice to the RV. The Smart Brake-equipped towed vehicle then plugs into the motorhome
and uses the existing trailer brake circuit to operate the supplemental braking system. This also allows you to switch between the
Smart Brake towed vehicle and any electric brake-equipped trailer without any changes.
Because most of the components are contained within the Smart Brain module, the installation time for the Smart
Brake has been reduced to an average of two hours versus the six hours required for the previous design. It's basically an "install it
and forget it" system. Once it's installed, there are no further adjustments, calibrations, or components to remove before driving the
vehicle. When you want to tow the vehicle, you simply hook up to the tow bar, plug in the electrical cord, connect the safety and breakaway
cables, and you are ready to tow.
Another benefit of the Smart Brake over competitive brands is that the cable that connects to the brake pedal arm
self-adjusts for slack when you first connect the Smart Brake. On other units, the cable length is fixed and you cannot adjust normally
adjustable pedals if you have them. The brakes will drag and heat up if you tighten the cable, and the brakes won't apply when towing if
the cable has too much slack in it. The Smart Brake will automatically set the cable to the correct tension when you initially plug in
the umbilical cord to prevent that from happening.
A version of the Smart Brake is also available for those drivers with hybrid vehicles, which does not utilize a
vacuum booster pump. The Smart Brake comes with a breakaway switch and the seven-pin connector cable to connect to the RV. It comes with
a trailer brake controller but can also be purchased without a controller for those RV owners who already have a trailer brake controller
or prefer a specific model.
In addition to the reduced installation time, the Smart Brake can be easily removed and transferred to a new
vehicle when you decide to trade in your towed vehicle for another model or newer year without adversely affecting the previous vehicle.
With the new upgraded features and competitive pricing that puts the Smart Brake at less than some portable systems, it appears that the
Smart Brake is going to be very popular with motorhome owners and definitely raises the bar for supplemental braking systems.
Multiple kits are available for practically every vehicle on the road today, including hybrids. Retail pricing
starts at $895.
A complete wiring harness is included to connect the Smart Brain to the receptacle and breakaway switch.
The Smart Brake utilizes a standard trailer brake controller, which is mounted in the motorhome.
The towed vehicle is connected to the RV via a standard seven-pin RV-style umbilical cord.
The Smart Brain is sealed and can be mounted behind the front bumper or in the towed vehicle's engine compartment.
The actuator cable is run through the floorboard and connects to the brake pedal arm.
The breakaway switch and seven-pin receptacle are mounted on the front of the towed vehicle.
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