SMI Braking Frequently Asked Questions



What model do I need?

There are 2 models to choose from. Air Force One is designed for coaches with air brakes. If you have air brakes, AFO is the industries best choice. AFO uses air to activate, there is no worry with your exhaust brake. The new Stay-IN-Play DUO will work for both gas and diesel coaches. With DUO, brake lights and deceleration are required so false or unwanted activations are eliminated. In addition, with two signals necessary to activate, there is no need for the delay technology found in all the box brakes. Total control, progressive braking, and no set up with the fastest no delay activation in the industry. For a gas rig, there is no other choice.


Will the SMI systems void my warranties?

The Magnuson-Moss Warranty Act is a United States federal law (15 U.S.C. 2301 et seq.). Enacted in 1975, it is the federal statute that governs warranties. It states that warranties cannot be voided unless the addition of the after market part is proven to be the cause of the failure of the warranted part. In short NO. Several Saturn dealers sell and install the SMI systems because they utilize the vehicle's brake systems the way they were designed.


Will Air Force One effect my air brakes?

In a word no. SMI worked with Spartan Chassis and Bendix to create the only air brake system that meets federal regulations. These regualtions are designed to protect the coach air supply as well as the towed vehicle in the event of a towing system failure.


How long is the warranty?

All SMI products are warranted for 5 years.


How long has SMI been in business?

SMI started in 1997. SMI is family owned and operated. We understand the importance of family. As a family, we have enjoyed RVing for many years. Having traveld for years in our own rigs, we understand the importance of providing products and support that give you the trouble-free traveling you are looking for.


Can your systems be user installed?

Each system comes with well written, easy to understand instructions so the user can install the system. We have a network of dealers and installers if you would prefer to have it installed for you.


Do you have a breakaway system?

Everything you need comes with each system including the breakaway system.


Where do the components go?

Both the DUO and AFO have a single operating unit that is small enough to be installed under the hood of any tow car. Both systems use the industries smallest actuator mounted on the brake arm so it is out of the way and does not have to be taken in and out each time you want to move the car.


Will these systems lock up my towed vehicles brakes?

Both the Stay-IN-Play and Air Force One systems are designed to duplicate your brake effort from the coach. Neither model is capable of locking up the towed vehicle brakes.


How does the Stay-IN-Play DUO know when to activate?

The brakes of the coach must to be applied AND you must create sufficient deceleration for the DUO to apply the towed vehicle brakes. The declaration is a user adjustable feature. The DUO CANNOT activate without the coach brakes, a decided advantage on steep grades.


How does Air Force One know to apply the brakes?

AFO requires air to activate. Due to the powerful nature of exhaust brakes, Air Force One is the best choice for diesel coaches.


I have air over hydraulic brakes, will Air Force One work?

Yes. In an air over hydraulic coach air is used to control how much brake effort is applied. Air Force One can easily accommodate these rigs.


How do these systems activate my power brakes?

To be an efficient system, the vacuum booster must be energized. This creates a soft pedal for the SMI systems to apply the brakes. Air Force One utilizes a patent pending process that converts air pressure into vacuum without a pump. The Stay-IN-Play DUO use an electronic pump.


Will either model wear my battery down?

AFO has no electronic draw on the towed vehicle. The DUO only draws power when it activates. This means that you can tow for several days without concern for your battery.


How can I get the installation instructions?

 Air Force One Installation Instructions


 Duo Braking Installation Instructions