Flat towing a Jeep or a truck behind a massive Class A motorhome feels fine until you actually have to hit the brakes. Hard. That’s when physics takes over. You’ve got 30,000 pounds of motorhome trying to stop, and a 5,000-pound SUV pushing it from behind like a frantic toddler. It's sketchy. This is exactly where the Demco Air Force One comes into play, and honestly, if you’re driving a coach with air brakes, there isn't much else that even comes close to this level of safety.
Most people starting out with "toads"—that’s RV speak for the car you tow—get overwhelmed by the options. You have portable boxes that sit on the floorboard, surge brakes, and cable systems. But the Air Force One is different. It’s a permanent, proportional braking system specifically engineered for motorhomes with air brake systems. It’s not just a "nice to have" accessory. In many states and provinces, having a supplemental brake system isn't just a suggestion; it’s the law. If your breakaway fails or your hitch snaps and that car goes flying into oncoming traffic, you’re looking at more than just a bad vacation.
How the Demco Air Force One Actually Works
The genius of this thing is how it talks to your motorhome. It uses the coach's own air supply. When you step on the brake pedal in your motorhome, the air pressure sent to the coach's brakes is also sent through a jumper line to the towed vehicle.
It’s proportional.
That word gets thrown around a lot in marketing, but here’s what it means in the real world: if you tap the brakes lightly to slow down for a distant red light, the car taps its brakes lightly. If a deer jumps out and you slam on the anchors, the car slams its brakes too. It mirrors your foot perfectly. Unlike "surging" systems that rely on the car's momentum pushing against the hitch, the Demco Air Force One reacts the exact millisecond you move your foot.
The installation involves two main parts. First, there’s the Operating Unit. This stays under the hood of your car. Then, there’s the Coach Kit. This is a small tank and valve assembly that taps into your motorhome’s air lines. Demco includes a "Total Termination" system, which is a fancy way of saying they’ve built in a fail-safe. Even if the air line between the RV and the car gets severed, the motorhome’s air system is protected. You won't lose your coach brakes just because the tow car had an issue. That’s a massive engineering win that a lot of people overlook when comparing cheaper alternatives.
Why the "Invisible" Factor Matters
Portable braking systems are a pain. Period. You have to lug a heavy box out of the trunk, wedge it into the driver’s seat, hook up a vacuum line, and plug it into the 12V outlet every single time you want to drive. Then you have to take it out when you want to go get groceries.
With the Demco Air Force One, once it’s installed, you basically forget it exists.
You plug in one small air hose between the coach and the car, attach the breakaway cable, and you’re done. That’s it. It’s "set it and forget it" technology. For people who move campsites every few days, saving ten minutes of wrestling with a heavy brake box is worth the higher upfront cost. It makes the transition from "driving mode" to "exploring mode" almost instant.
The Physics of the Vacuum Pump
Most modern cars use vacuum-assist brakes. When the engine is off, you usually only have one or two "power" stops left before the pedal gets rock hard and impossible to push. The Air Force One handles this by using the air pressure from the coach to create a vacuum for the car's brake booster. It essentially "energizes" the car's power brakes while it's being towed. This means the system doesn't have to push as hard on the pedal to get the car to stop. It's easier on the car’s hardware and much more effective in emergency maneuvers.
Installation Isn't for the Faint of Heart
Let’s be real: installing this is a project. If you aren't comfortable cutting into your motorhome’s air brake lines, don't do it yourself. Seriously. You are dealing with the primary safety system of a massive vehicle. Most people head to a professional shop or an RV service center.
The process involves:
- Mounting the air tank and control valve on the coach chassis.
- Tapping into the "metered" air line (the one that gets pressure when you hit the pedal).
- Mounting the operating unit inside the car’s engine bay.
- Installing an actuator—a small cylinder—on the brake pedal arm of the car.
- Running the breakaway switch wires.
It’s a lot of plumbing. But the result is a clean, professional setup. There are no wires hanging under the dash and no bulky boxes taking up legroom.
Common Misconceptions and Points of Failure
One thing people get wrong is thinking this works on gas motorhomes. It doesn't. If you have a gas coach (F53 chassis, etc.), you don’t have an air compressor or air brakes. You’d want the Demco Stay-IN-Play DUO instead. The Air Force One is strictly for diesel pushers or any rig with a true air brake system.
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Another "gotcha" is the breakaway system. Every now and then, I see someone who didn't test their breakaway battery or wiring. If the car ever uncouples, the Air Force One uses a small onboard air reserve to lock the car's brakes and bring it to a stop. If that circuit is dead, the car is a 5,000-pound unguided missile. You have to test that pin regularly. Just pull it and see if the brakes engage. Simple, but literally a lifesaver.
Also, watch your pedal clearance. The actuator that pulls the brake pedal needs to be mounted perfectly straight. If it’s at an angle, it can wear out the cable or, worse, bind up. It’s a mechanical connection, so physics applies. A little bit of friction over 10,000 miles of towing adds up.
Real World Performance
I've talked to dozens of owners who have switched from portable units to the Demco Air Force One. The consensus is always the same: "I wish I did this sooner."
The braking feel is natural. There’s no "jerking" sensation when the car's brakes kick in. In a heavy rainstorm or on a steep mountain grade like the Grapevine in California or the Eisenhower Pass in Colorado, having the car helping you slow down—instead of pushing you—is the difference between a relaxed drive and white-knuckling the steering wheel. It reduces heat buildup in your coach's brakes, which prevents brake fade.
Comparing the Cost
Yeah, it’s expensive. You’re looking at $1,200 to $1,500 for the hardware, plus another $600 to $1,000 for labor if you aren't doing it yourself.
A portable unit might cost $1,100 total.
But look at the trade-off. Over five years of RVing, you might hook and unhook that car 200 times. If the Air Force One saves you 10 minutes each time, that’s over 30 hours of your life you aren't spent kneeling on the pavement or swearing at a plastic box. Plus, the resale value on these systems is high. RVers know the Demco name. It’s a premium brand for a reason.
Practical Steps for Potential Buyers
If you’re considering the Demco Air Force One, don't just click "buy" on the first website you see.
First, verify your motorhome’s chassis. Ensure you have the necessary air taps. Most modern Freightliner or Spartan chassis make this easy, but older rigs might require more specific fittings.
Second, check your towed vehicle's floorboard. Some cars have very little room around the brake pedal arm. You need to make sure the actuator cylinder has enough clearance to move freely without hitting the trim or the steering column.
Third, decide who is doing the work. If you're a DIYer, Demco’s instructions are actually pretty good—they aren't translated poorly or filled with jargon. They provide clear diagrams. But you’ll need a good set of tools and a full day. If you’re hiring a pro, ask them if they’ve done an "AFO" install before. It’s a specific skill set.
Lastly, don't forget the lighting. The Air Force One handles the stopping, but you still need a wiring kit (like a diode kit) to make sure your car’s turn signals and brake lights mirror the coach. They are separate systems, though many people install them at the same time.
Stopping a motorhome is about managed energy. The Demco Air Force One is simply the most efficient way to manage that energy when you have a car trailing behind you. It’s elegant, it’s permanent, and it works exactly the way it should every single time you touch the pedal. It’s one of those rare pieces of RV tech that actually lives up to the hype.
Check your local laws regarding breakaway systems and supplemental braking. Most jurisdictions require them for anything over 3,000 pounds. Don't risk your insurance or your safety by skipping this. Get the right system, get it installed correctly, and enjoy the peace of mind that comes with knowing your "toad" isn't going to overtake you on a 6% grade.