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Demco Air Force One Flat Tow Brake System for RVs w/ Air Brakes - Proportional

Demco Air Force One Flat Tow Brake System for RVs w/ Air Brakes - Proportional

Item # SM99243
Our Price: $1,329.00
You Save: $543.13
Tow Bar Braking Systems

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Get safe, smooth braking for your towed car with this truly proportional braking system. Car slows perfectly in sync with your RV. Installs permanently so you can just plug in and go. Low-profile design keeps it out of sight and out of the way. Great Prices for the best tow bar braking systems from Demco. Demco Air Force One Flat Tow Brake System for RVs w/ Air Brakes - Proportional part number SM99243 can be ordered online at or call 1-800-940-8924 for expert service.
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Demco Tow Bar Braking Systems - SM99243

  • Brake Systems
  • Air Brakes
  • Proportional System
  • Demco
  • Fixed System
  • Power Assist Brake Compatible
  • One Time Set-Up

Get safe, smooth braking for your towed car with this truly proportional braking system. Car slows perfectly in sync with your RV. Installs permanently so you can just plug in and go. Low-profile design keeps it out of sight and out of the way.


  • Get the safest and most even braking while flat towing
    • Uses the air pressure from your RV's brake line to apply towed car's brakes at the same time, with the same intensity
    • Applies brakes only when needed: no false braking
  • Plug in and go
    • System automatically turns on when you connect your towed car to the RV
    • Low-profile components install permanently and stay tucked out of sight
  • Monitor your towed car's braking with LED indicator on car's dash
    • Lights up when the brakes are applied
  • Avoid damage from over-braking: reactivates car's vacuum-assisted braking
  • Protect your motorhome: system meets FMVSS safety guidelines for RVs with air brakes
  • Get everything you need: includes breakaway switch, coiled air hose, and all necessary components
    • Add the wireless Coachlink (SM99945 - sold separately) to conveniently monitor the braking system from the RV cab
  • Made in the USA


  • Application: motorhomes with air brakes
    • Can accommodate air-over-hydraulic brakes with additional 1/4" DOT air line (DM16114 - sold separately)
  • Compatible with hybrids and other cars with continuous-power-assist brakes
  • Coiled air hose length when fully stretched: 7'
  • Breakaway cable length when fully stretched: 7'
  • 5-Year warranty

air force one review

"This is the top system I recommend if you have air brakes. Quality, reliable, tried-and-true. It just always works."

Do I Need a Braking System for Flat Towing?

A braking system is a must when towing a vehicle behind your motorhome. Without it, the weight of the towed car can create a safety hazard, strain your RV's brakes, and affect its warranty. Most states legally require a supplemental braking system, so if you don't use one and you end up in an accident (which is more likely since your RV takes longer to come to a full stop), your insurance and liability headache just doubled. You also won't have any breakaway system; if there's an accidental disconnect, there's nothing to bring your car to a stop.

Pros of a Permanent System

The Air Force One is a permanent braking system, which means that it's a one-and-done. Once it's installed, there's no more setup that you have to do. When you plug in the air jumper and the power cord at the front of your vehicle, the system automatically turns on. Just like that, you're ready to flat tow.

While the components are installed permanently in your RV and towed car, they remain concealed and inconspicuous. None of them will interfere with normal driving, and most of the time they are invisible.

How Does the Demco Air Force One Work?

The Demco Air Force One offers truly proportional braking for the safest and most comfortable flat towing experience. Proportional braking means that when you apply the brakes in your RV, the braking system will engage the brakes of your toad (towed vehicle) at the same time and with the same intensity. Whether it's a gradual slow down to a red light or a sudden stop in an emergency, your toad and RV will brake together.

How does the Air Force 1 work?

To achieve this, the Air Force One ties directly into your motorhome's air brakes and uses the same air pressure that results from you pressing the brake pedal in your coach to pull down the brake pedal in your toad. The result is uniform, real-time braking that exactly mirrors your RV.

This is a huge advantage over inertia-based systems, where the braking is triggered by sensing the forward momentum of your toad. While often effective, this method creates the potential for false braking, where something as simple as rough terrain can activate the system when it's not needed. Not only does this make for a rough ride, but it can also prematurely wear down your toad's brakes over time. The Air Force One will only turn on when you need it, so you can avoid any false braking.

To deliver the pressurized air needed to activate your toad's brakes, the coach air connection assembly taps directly into your RV's air brake lines.

Demco Air Force One air tank diagram

A pressure protection valve collects air from your RV's supply air line and stores it in an air reservoir tank so that it's ready to use when you need it. This 1-way check valve ensures that your RV's air lines maintain consistent pressure so that the motorhome's brakes will not be affected by the Air Force One. It meets Federal Motor Vehicle Safety Standard (FMVSS) guidelines requiring that supplemental braking systems use a separate air supply and activation relay valve.

On the other side of the air tank, the service relay valve taps into the coach's metered air line. When you press the brake pedal in your RV, the same pressure that's sent to the brakes is sent to the air connection assembly through the service relay valve. The delivery relay valve then sends the pressurized air to the operating unit via the coiled jumper hose connecting the motorhome and toad.

Main unit of Air Force 1

The main operating unit, mounted under the hood of the toad, receives the air from the coach and sends it to the actuating cylinder that attaches to your vehicle's brake pedal. The cylinder will then pull the pedal down and apply the brakes.

Demco Air Force 1 cylinder mounted on brake pedal

With this system, the brakes are applied in the toad at the same time, with the same amount of pressure as in the motorhome. This is what makes it truly proportional.

Vacuum-Assist Braking Means Natural Braking

When you're driving, your vehicle uses vacuum pressure to create the force needed to bring the car to a stop. On most vehicles, this vacuum-assist function does not work when the engine is off. As a result, a lot of supplemental braking systems have to use an excessive amount of pressure to brake the toad.

The Air Force One, on the other hand, reactivates your car's vacuum-assist function by tying into its vacuum line and using the air pressure from the RV to create the needed vacuum. This way your car will brake evenly and naturally as it's being towed, so there's less risk of damage.

Installing the Air Force One

Air Force One review

"In my experience, this has the most user-friendly installation of all the permanent braking systems. The RV side of the install can be tricky though! It's a little intimidating to cut into the air lines."

The Air Force One comes in 3 main pieces: the coach air connection assembly, the operating unit, and the actuating cylinder.

Where to mount the air tank of the Air Force One

The coach air connection assembly mounts on the underside of your motorhome, wherever you can find an open, secure place for it. You'll connect it to the supply air line and the metered air line on your RV using the included tees. You'll then route an air hose to the quick-connector on the back of your motorhome.

Quick Tip: The coach air connection assembly needs to be mounted in a location where the air lines will not be exposed to direct heat sources or moving parts; in front of the rear axle is often a good location.

Quick-disconnect air valve on Air Force 1

The coiled air hose, also called a jumper, runs between the RV and the toad and connects the coach air assembly to the operating unit. You'll plug it into the quick-connects at the same time as you hook up your tow bar.

Where to mount operating unit of Air Force 1

The operating unit will typically install under your car's hood. It's designed with a low profile so you can easily find somewhere to put it. Once the unit's mounted, you'll connect the air lines and splice the wires to the breakaway switch, which you'll need to install on the front of your toad.

Air Force One actuator on brake pedal

The final piece is the actuating cylinder, the part that actually presses the brake pedal down in your towed car. It will mount permanently to the arm of the brake pedal and anchor to the firewall. Though it is permanent, it will not interfere with everyday driving. In most vehicles, it is tucked up where you can't even see it.

It connects to the operating unit via an air hose you'll need to run through the firewall. In most cases, you can cut a slit in the hood release cable grommet to pass it through. Either way, you shouldn't have to do any drilling to get the air line hooked up.

There are a lot of steps to installing the Air Force One, but the truth is that there is no "easy" braking system. It's just a question of what kind is best for you. The advantage of the Air Force One is that, once it's installed, you shouldn't have to touch it again. You don't have to find a place to store it between trips or set it up each time you tow. You just connect your electrical cord and jumper hose and you'll be ready to go.

Built-In Safety Features

Air Force One braking monitor

Included with the Air Force One is an LED indicator light for safety and peace of mind. This LED, mounted in the toad (on the dash or on the back of the rearview mirror) and visible in your RV's backup camera, will light up whenever your toad is actively braking. It's a simple way to keep tabs on whether the system is working properly or if something is going wrong.

Most supplemental braking systems have a method of letting you know when they activate, but not all of them are checking if the toad is actually braking. There could be an error that causes the system to activate without actually applying the toad's brakes. Or your brake pedal might be continuously depressed when it shouldn't be. But unless you have a system that's monitoring the pedal, you won't know it until the damage is already done. This indicator, however, connects directly to a reed switch on the actuator so it only lights up when the pedal is depressed.

If there's a strong glare on your toad's windshield, the LED light strip might be hard to see. The wireless Coachlink system (SM99945 - sold separately) is a great solution to this problem; the monitor mounts right on your RV's dashboard so it's directly in view. This is a great add-on for convenience and peace of mind.

Air Force 1 Breakaway switch

The Air Force One also comes with a breakaway system. The breakaway system ensures that your car will come safely to a stop if it accidentally detaches from the RV while you are towing. A switch mounts to the front of the towed vehicle. This switch - which wires to the operating unit - includes a pin that connects to your RV's hitch receiver with a breakaway cable. If the car separates, the cable pulls the pin from the switch, triggering the system. A reserve air supply stored in the operating unit will apply your towed car's brakes. This system also has total coach protection built in: if there is a separation, the motorhome's air supply gets sealed off, so its brakes will continue to function as normal.

What You Need to Flat Tow

Flat towing can be a much more convenient way to take your car RVing with you than using a trailer or a tow dolly. It'll save you storage space both at home and at the campsite, and it takes less time and hassle to hook up.

To flat tow your vehicle, there are 5 basic components you're going to need: a tow bar, a base plate kit, a safety cable set, tow bar wiring, and a flat tow braking system.

For the RV Between the RV and Towed Car For the Towed Car
Hitch Tow bar Base plate
Wiring plug Safety cables Braking system
Wiring adapter cord Wiring kit/diodes

The custom-fit base plate installs on the frame of your toad so you can connect the car to your RV with a tow bar. Hook up safety cables between the vehicles to ensure that the toad does not separate from the motorhome if the tow bar becomes detached. Tow bar wiring syncs your vehicle's signal lights with your motorhome's tail lights, as required by law in most states. Finally, the flat tow braking system - also required in most states - activates the brakes in the toad when you hit the brakes in the RV, making for smoother, safer braking, and preventing wear on your motorhome.

9599007 AFO115 Demco SBS (Formerly SMI) Air Force 1 Supplemental Braking System for Motorhomes with Air Brakes - Proportional

Replaces Demco SBS SM99202 and SM99243


Installation Details SM99243 Installation instructionsAlternate Instructions SM99243 Installation instructions

This Product Fits The Following Vehicles

Customer Satisfaction Score:

Customer Reviews

Demco Air Force One Flat Tow Brake System for RVs w/ Air Brakes - Proportional - SM99243

Average Customer Rating:  4.8 out of 5 stars   (326 Customer Reviews)

Get safe, smooth braking for your towed car with this truly proportional braking system. Car slows perfectly in sync with your RV. Installs permanently so you can just plug in and go. Low-profile design keeps it out of sight and out of the way.


I wouldn't use anything else! Once this system is installed it's literally plug-and-play. Nothing to move or install into the car, each time you tow. Just plug it into the coach's air break system and you're done. Install video from etrailer made it even easier to complete.

You do need a bit of mechanical guidance/assistance as you're connecting to both your vehicles and coaches breaking system but it has worked flawlessly for over 11,000 miles and in some pretty intense traffic.

Chevrolet Equinox

I purchased this as part of a package which included; Hitch and wiring for my 2022 Equinox, Base plate, Tow Bar, brake System and connecting air hose, break away cables, LED tow lights with wiring harness, and a trickle charger to keep the Equinox battery from going dead while I was towing it behind my class A RV.
I had etrailer do the install of all the components on my car and RV. All the workmanship was excellent and done in the amount of time they said it would take. Also because they did not have a video of this equipment being put on this year and model vehicle, I gave them permission to make a video(which added a extra day and a half to the install)and the installation was free. Everything has worked perfectly and I couldn't be happier. Etrailer is my go to for anything towing and also RV parts.

2014 Honda CR-V

AF1 is amazing so far. I did the installation by myself. I have a 2014 Honda CR-V and bought it for towing. Watching the video helped me through it. The car installation portion was pretty straight forward. The video is better than the instructions overall, but I read through the entire instructions before beginning. I was able to install the RV tank without putting the rig on a lift. Depending on how big you are and flexibility, it can be done with the RV on the just takes longer. Also, I would recommend knowing where you are going to mount your RV tank. I mounted the tank near the rear and didn’t have enough brake tube after doing the car. Picked up an extra 20 ft at Autozone or order the tube with etrailer.

The customer service center is very helpful too. Many thanks to Mariah for the outstanding assistance. Finally, I would say that if you order the brackets to mount the emergency brake away for your car, you may have to cut them down with a grinder. It is so much nicer not putting the brake buddy in the car now. Looking forward to enjoying it on trips. I drove the rig about 20 miles yesterday, and the light came on and I honestly couldn’t tell the car was back there other than looking in the video and seeing the light on the car during braking. Highly recommend this unit.

Darryl W.


5.0 Product is working great! No issues. Minor adjustment to brake cable after a year. It took 5 mins.


I believe the AFO is the best supplemental braking system for air brakes on the market today. Probably the most expensive also. A lot of work to install but a good system that is truly proportional and safe to use with an air brake system.

Bruce P.


We have used our AFO for over 12,000 miles towing a 2018 Chevrolet Colorado. It seems to be working fine but is really hard to know for sure. It is difficult to see the LED light strip in the camera during bright daylight. When I installed the AFO, etrailer was very helpful even returning my call on a Sunday. I also added a plastic stub next to the connectors on both the RV and toad that very conveniently stores the plastic cover when the brakes are not connected so they do not get lost. I tried to contact etrailer with my simple improvement but no one seemed interested.


The Air Force one was not an easy install for me because I’m old and I don’t get around like I used to but it was not impossible. However, in my opinion, it is the best supplemental braking system for flat towing. The best part about it is my Allegro Bus came with the system already installed on the coach and once you install it on your towed vehicle you don’t have to deal with any of that to get on the road. If it takes me more than ten minutes to hook everything up and get in the coach ready to drive away then I've done something wrong.

2012 Saturn Relay

"Out of sight, out of mind" would be the best description I could offer for the Air Force One supplemental braking system! When properly installed, it's effective as well as quick and easy to hook up. Connect the tow bar, safety cables, safety switch cable, tow plug and air line, you're done! Five minutes at most.

I did add a couple of features to my towing system:

1. Using a relay and the extra wire in the connector to the coach, I installed the LED indicator strip on the dash of the coach; no need to rely on the back-up camera to verify operation of the brake cylinder. Coaches that have a tow connector are usually equipped with a power wire to the cab for electric brakes - this wire is a good way to get the indicator signal to the front of the motorhome.

2. I used the 12 V power connection from the coach to connect a charging wire to the car battery to ensure it would not discharge; I used an auto-resetting breaker with a rating below the glass fuse in the 12 V circuit to prevent a fuse from blowing if the charge current gets to high.

In all, a great investment! I have an article I wrote on the install if anyone is interested.

2016 GMC Canyon

Vehicle 2016 GMC Canyon Diesel.
of the SMI Air Force One supplementary braking system was not too difficult. The instructions from SMI were good as was the video from etrailer. The only reason that I didn't give it a 5 star is because the air cylinder installation on the brake pedal was complicated by an unusual shape of the brake pedal arm. I eventually found a solution.
Tapping into the truck's vacuum line was a little difficult but the kit included everything I needed to T into the vacuum line and install the check valves.
All in all not a bad installation, this summer we'll see how it holds up.

2014 Jeep Wrangler

Excellent system. Takes a little bit to install, but worth the effort. Our toad is a 2021 Jeep Wrangler with the ecodiesel. Some of the passes that we did were 14 degree and the braking worked great!


I’ve fitted it to my Jeep Wrangler then taken of and fitted to our new Jeep Grand Cherokee. Works perfectly . I had used our 53ft coach without it and in an emergency stop, was a problem stopping in the rain. Now we have had a couple of fast stops and it works great, would be without it.

Ford F-150

Very pleased with the Air Force One braking system. I installed it myself on my Newmar Dutch Star and it works great for towing my F150.


Took some time to route the lines but the system works well


I installed it myself, followed the eTrailer installation video. I have used it a year, works great, have put over 3000 miles on it. No issues. Struggled with using a portable brake system and decided to do it right. It was the right choice.



Perfect, way better that the portable device


Came with everything I needed to install it. Great quality and works fantastic!

Jon M.


Works great!

2004 Chevrolet Avalanche

Pulled entire length of route 66 and then some. We had absolutely no issues with all of our etrailer equipment. Thanks for all of your help.


This braking system has been nearly flawless for me since installation.
Only tow coomplaints to speak of, as follows:
1. During install of the firewall screw for the acutator, the screw ended up causing a short in my vehicle. I had to spend many hours troubleshooting and Demco support was adamant it was not their products fault.
2. The actuator has gotten sticky over time and does not reset to the correct location after braking, causing the light to stay on longer than it should.


We love our Air Force One braking system. The confidence it was done right by etrailer allows us to tow our 4x4 van without worrying about it!


Great product and easy to follow detailed instructions.


I just received it with a hole in the corner of the box. I didn’t see any visible damage, but I’m not the one installing it with the holidays. I expected it to be late.

2014 Jeep Wrangler

Just finished a 10,000 mile trip trailering a 2014 Jeep Wrangler with Air Force One braking system and we are very satisfied with the product. No issues or failures and once installed, it is very easy to use. We can connect and disconnect from the Air Force One and our Blue Ox towing system in 2-3 minutes.

Joe T.


After a year, we are still happy with the AF One. We had one issue where it didn’t work and it turned out we let a little grime get into the air fitting. Took some time to figure it out but we cleaned with compressed air and the problem went away. Lessen learned it to keep rubber covers on the air fittings when not in use.


Installation was easy, compact and out of the way. Had a little problem finding controller location due to clearance. Ended up using velcro on top of the fuse box to hold the controller in place.



Questionable? This year it Felt like the truck in tow was pushing me during mid to heavy braking. Pulled over a couple of times to verify pedal was being pushed down. Verified vacuum lines from your system to the brake vacuum line was tight. It acted like the vacuum assist was not working. I need to find time to ask you about this problem.

Etrailer Expert

Katrina B.


So, it seems that this is going to be better diagnosed through troubleshooting with the manufacturer. I have sent you Demco's contact information and their hours of operation in a seperate email.


Works confidently! The activation cylinder on brake pedal arm rattles and doesn't adjust well to moving brake pedal to driver position. It also lights up the LED on my rear view mirror when not being towed.

Ford Ranger

This system has worked great for my flat towing of my Ford Ranger. Had my local dealer install the system for me and have had not one single issue with the operation.



After one year and more than 10k miles have not had a single problem with the Air Force One braking system on my 2019 Ford Ranger.

2022 Jeep Grand Cherokee L

Simple installation. Very good instructions from Demco.


I ordered an Air Force One breaking system one year ago, for my 2019 Allegro Bus 45OPP, and my 2012 Honda CR-V.
I paid $1080.00 with free shipping from E-Trailer. The unit arrived in perfect condition. I installed the system myself, in about three hours on the Motorhome. I had previously ordered a special hose/ tube cutter. The only part of the installation that was a little intimidating was cutting the correct air lines on the coach, however after viewing the installation video everything was made clear.
The install on the Honda took about two hours, I did have to call the people at E-Trailer , but they cleared up my questions.


Seems to be working well. Wife and I did our own installation and it was challenging. Standing on my head under the dashboard mounting the breaking air cylinder at the brake was tough but doable. Tapping into the air brake system on our motorhome also challenging but it all appears to do the job. Glad that job is behind us.

Show More Reviews

See what our Experts say about this Demco Tow Bar Braking Systems

  • Potential Issues if a Demco Air Force One Braking System is Engaging the Parking Brake on a Sierra
    I have not come across this being an issue when using the Demco Air Force One Supplemental Braking System # SM99243 in your 2023 GMC Sierra 1500 before. So I went ahead and reached out to the manufacturer to see if they have come across this before and I have included what they were able to tell me below. "It sounds like when the customer disconnects the negative cable, the truck is still finding a ground through either the tow bar or lighting cables. As a result the truck acts as if...
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  • Where to Mount Module of SMI Air Force One on 2019 Jeep Cherokee Latitude
    The picture is somewhat hard to understand what's going on, but it looks like they mounted the module of the SMI Air Force One Supplemental Braking System # SM99243 horizontally in front of the radiator. It would appear it wouldn't affect the air flow to the radiator too much but I'd probably keep an eye on the fluid temperature gauge. As long as it's securely mounted it would be fine. I attached a picture that shows where we mounted the box on a similar 2018 Cherokee as well. The install...
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    Image 1 for
  • SMI Air Force One Module Dimensions
    The overall length of the module that comes with the Air Force One # SM99243 is 10-1/2 inches from handle to handle but the actual box part is 8-1/2 inches. It is 5-3/8 inches wide and 1-1/4 inches tall. Check out the picture I attached to see all of the dimensions.
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  • Estimated Installation Time for SMI Air Force One Braking System
    I reached out to my contact at SMI and he said that for both the RV and your 2017 Chevy Silverado you're looking at a total install time of around 5 to 6 hours for the Air Force One Braking System # SM99243. I have attached an installation video on the 2017 Silverado that you can use for reference along with the written manual.
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  • Will Air Brake System Apply Supplemental Braking System Brakes
    Supplemental braking like the SMI Air Force One # SM99243 will start trying to activate the towed vehicle brakes when the brake lights of the tow vehicle apply. So if the engine brakes apply the brake lights then yes the system would start working to stop the vehicle.
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  • Does the Air Force One Brake System Come with Everything Needed for the Installation
    The SMI Air Force One Supplemental Braking System # SM99243 comes with everything you need for it to work with a motorhome that has air brakes. The only time that something else might be needed is if you have air-over-hydraulic brakes. In that case you may need additional 1/4" DOT air line. Attached is a review video and the installation instructions for you to check out. A complete flat towing setup includes a base plate kit, tow bar, safety cables, vehicle tow bar wiring, a supplemental...
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  • Is a Third Check Valve Needed for the SMI Air Force One on a 2018 Ford Edge
    I saw the tech note that you were referring to about some of the newer Ford vehicles requiring a third check valve. However, your 2018 Ford Edge has a factory check valve on the brake booster lines so there is not a third one needed and you will have everything you need with the two that are included with the SMI Air Force One Supplemental Braking System part # SM99243. This is an excellent system that will work great for you so long as your motorhome has air brakes. I called my contact...
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  • Does LED Indicator Light of SMI Air Force One Light Up When Vehicle isn't Connected
    The LED notification strip that typically attaches to the rearview mirror of the vehicle being flat towed will not always light up when the vehicle brakes are applied. It would have to be connected to the tow vehicle. I attached a diagram for how it wires up as well.
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  • Can SMI Supplemental Braking System be Used with 2006 Tiffin Allegro Motorhome
    Our fit guide info for the SMI Air Force One Supplemental Braking System for Motor Homes with Air Brakes # SM99243 is relative to vehicles that are getting flat towed. You'd be using the Tiffin Allegro bus as a tow vehicle and not a towed vehicle which is why it's showing up as "not a fit". As long as your Allegro as air brakes this kit will work well on it.
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  • Is Air Force One Supplemental Braking System Compatible with Air over Hydraulic Motorhome Brakes
    Yes, the Air Force One part # SM99243 that you referenced is compatible with air over hydraulic brakes like what your 2003 Safari Cheetah has that is built on a Roadmaster M4R Series Chassis. I attached a review video for this system for you to check out as well.
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  • Video of Install for SMI Air Force One Supplemental Braking System on 2017 Ford F-150
    We are not affiliated in any way with installers apart from our own, which are located in Wentzville, MO so there is not a list I can offer for installation of the SMI Air Force One Supplemental Braking System for Motor Homes with Air Brakes # SM99243. However, if you make some calls to certified mechanics or shops in your area you are very likely to find someone who is qualified to do the installation. I did add a pair of links to video installations showing this system being installed...
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  • Air Force One Supplemental Braking System Actuates Vehicle Brakes When Not Attached to RV
    I spoke with my contact at SMI, the manufacturer of the Air Force One braking system. He had a few possibilities that he recommended you have checked. Where the cable that joins the actuator cylinder on the brake pedal, make sure that there's about 1/4 to 1/2 an inch of slack in the cable. Also, if the vehicle has adjustable pedals, make sure that the pedals are move as close to the seat as they'll go when the tension on the cable is set. This procedure is outlined in Step 7 of the installation...
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  • How Installed SMI Air Force One Receives Power While 2016 GMC Canyon Being Towed
    The power and functionality requirements of the Air Force One System, Item # SM99243, are taken care of when it is directly attached to the vehicle battery during installation. Everything will still function even if the negative cable is off of the battery because only the positive terminal and a ground location are needed The Air Force One works by engaging the brakes for a towed vehicle when it receives air from the coach air connection. It diverts a matching amount of air through...
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  • LED Monitor on Demco SBS Air Force One Supplemental Braking System Stays Illuminated
    You'll want to review the installation of the actuator read switch for the LED monitor, as incorrectly installing it can cause it to ground out, in which case it'll stay illuminated all the time. The procedure is described in step 7, on page 25 of the instructions. I've inked you to the installation instructions for the Air Force One # SM99243 braking system.
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  • SMI Air Force One Brake System Air Line Connection in Coach Recommendation
    In the install instructions for the SMI Air Force One system part # SM99243 that you referenced the correct line to use for the Spartan Chassis is pointed out. I attached that picture. The line to use is the coach's supply air hose. This line goes from the service relay valve to the braking air tank. It is 5/8 inch in outer diameter. This line is normally green and should not be confused with the treadle valve hose which is 3/8 inch in diameter.
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  • Does the Reed Switch Eliminate the Brake Light Switch on an SMI Braking System
    According to the installation instructions for the SMI Air Force One Supplemental Braking System for Motor Homes with Air Brakes part # SM99243, the reed switch attached to the actuator will power the LED. The brake switch will no longer be providing the signal for the monitor light. Exercise caution when installing the reed switch. If the reed switch arcs to ground, it will either no longer work or cause the LED to stay illuminated at all times. You can reference the installation of the...
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  • Installing SMI Air Force One Supplemental Braking System on 40 Foot Dutchcraft on Spartan Chassis
    When installing the SMI Air Force One Supplemental Braking System For Motor Homes with Air Brakes # SM99243 you will need to find the supply air line and the metered air line. On the Dutchcraft motor home on the Spartan Chassis the larger 5/8 inch line is the supply air line, and the smaller 3/8 inch line below the supply air line is the metered air line. I have attached a photo showing witch line is the supply and which line is the metered.
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  • Finding Where to Connect Air Lines to Motorhome to Install SMI Air Force One
    When installing the SMI Air Force One Supplemental Braking System For Motor Homes with Air Brakes # SM99243 you will need to find the supply air line and the metered air line on the motorhome. On the Monoco Knight 34foot Road master chassis 2003 model the larger 5/8 inch line is the supply air line, and the smaller 3/8 inch line below the supply air line is the metered air line. See attached picture to see them pointed out. It sounds like what you found so far is not the service relay...
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  • How Many Amps Does Demco SBS Air Force One Braking System Draw
    I reached out to Demco, who told me the Demco SBS Air Force One Supplemental Braking System for Motorhomes with Air Brakes # SM99243 draws less than 1 amp. They told me the the only power used is to light up an LED on the back of the towed vehicle's review mirror to indicate that the brakes are being applied in the towed vehicle, and that is only when the brakes are applied. I have added a link to a video review for you to check out as well of the Demco SBS Air Force One Supplemental Braking...
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  • Troubleshooting the Brake Lights Not Coming on in my Flat Towed Vehicle
    It sounds like you are more likely having and issue with your tow bar wiring rather than the Demco SBS Air Force One Supplemental Braking System # SM99243. You can test this by testing your Air Force One system. Depress the break and verify that the LED indicator light is coming on and that the actuator is pulling the brake pedal in your towed vehicle. If that is happening, then the Air Force One is working properly. The Air Force One is not what provides power to illuminate your brake...
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  • Compatibility of Flat Towing 2014-2016 GMC Terrain and SMI Air Force One Braking System
    The GMC Terrain models from 2014 through 2016 can call be flat towed four wheels down, but it is recommended to have a speed restriction of 65 mph on all of these models when doing so. It is also recommended to start the vehicle and let it run for 5 minutes prior to towing and at each fuel stop. This gets the moving components properly lubricated to prevent damage. You will also want to let the engine idle for 3 minutes or more prior to driving after towing it. You will also want to...
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  • Keeping Water Out of Air Force One Braking System in Automatic Car Wash
    I spoke with my contact at Demco and he insisted that while it was unlikely that the cap that goes over the air connection on the # SM99243 would come off in an automatic car wash, they recommend using a zip tie around the cap on the connection to keep it secure. Typically the cap would only come off when they are worn down and stretched out. Using a zip tie around the base will keep even the most worn down cap from coming off while going through an automatic car wash.
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  • Do I Need the Air Tank for the Demco Air Force One in a 2002 Prevost?
    You're welcome! No, you won't have it. That's a newer addition to motorhomes. You'll need to install the air tank that comes with the Demco Air Force One Supplemental Braking System for Motorhomes with Air Brakes item # SM99243.
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  • Is SMI Air Force One Supplemental Braking System Transferrable Between Cars?
    The SMI Air Force One Supplemental Braking System for Motor Homes with Air Brakes # SM99243 is not transferable between vehicles and once it gets installed it is there during normal driving but will not have any effect on your Tahoe whatsoever. As for how long it takes a normal person to install, that is not something I would be able to quantify; there are simply too many variables. Someone with a bit of mechanical know-how could do it, but there are some involved aspects, as you can see...
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