SMI Second Vehicle Kit for Air Force One Supplemental Braking System

SMI Second Vehicle Kit for Air Force One Supplemental Braking System

Item # SM99209

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SM99209 - Second Vehicle Kit SMI Tow Bar Braking Systems
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In Use/Installed

  • Tow Bar Braking Systems
  • Second Vehicle Kit
  • SMI
Easily tow your other vehicle without having to install an entirely new SMI Air Force One supplemental braking system. Includes wiring, air lines and hardware. Call 800-298-8924 to order SMI accessories and parts part number SM99209 or order online at Free expert support on all SMI products. Guaranteed Lowest Price and Fastest Shipping for SMI Second Vehicle Kit for Air Force One Supplemental Braking System. Accessories and Parts reviews from real customers.

  • All Info
  • Reviews (9)
  • Q & A (13)
  • Videos (4)
  • Photos
  • Why etrailer?

SMI Accessories and Parts - SM99209

Easily tow your other vehicle without having to install an entirely new SMI Air Force One supplemental braking system. Includes wiring, air lines and hardware.


  • Lets you use your SMI Air Force One supplemental braking system (SM99202) with an additional vehicle
  • Necessary installation components and an instructional DVD included
  • Made in the USA
  • 5-Year warranty

6271 Additional Vehicle Kit for Air Force One Supplemental Proportional Braking System by SMI

Replaces SMI SM99209 and SM99213

Video of SMI Second Vehicle Kit for Air Force One Supplemental Braking System

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for SMI Tow Bar Braking Systems SM99209 Review

Today we're going to be taking a look at the SMI Second Vehicle Kit for Air Forced One Supplemental Braking System. This kit lets you use your SMI Air Forced One Supplemental Braking System with an additional or secondary vehicle. The braking system applies the towed vehicle's brakes in proportion to the braking action of the RV. This means that the towed vehicle's brakes are actually activated at the same time and with the same intensity as those in the coach. This is a one-time set-up, so there's no need to remove or activate each time you're ready to tow. The operating unit, which is this box, and the actuating cylinder stay hidden once they're fully installed. That way everything is out of the way when you're vehicle is disconnected from the RV and when you're driving it like normal. The system automatically functions when the towed vehicle is connected to the RV. You'll just need to make your basic connections and then you're ready to hit the road. This right here is an LED Coach Notification System that illuminates when the towed vehicle's brakes are applied.

This can be connected to the towed vehicle's . Excuse me, it gets connected with the towed vehicle's brake lights switch and that's going to ensure proper reading. This light can install on the RV's dash or you can save time by attaching the monitor light to the back of the rear view mirror of the towed vehicle. This way you can see the light from your RV's backup camera or rear view mirror. Now the vacuum-assisted function of the towed vehicle is activated with air from the coach's brakes. Less force is needed to move the brake pedal in the vehicle which results in a more natural braking and less risk of damage. All the necessary tubing that you need for the vacuum system and for the air lines, all that's going to be included.

It's also going to include all the necessary wiring. You're also going to get a breakaway kit. Your breakaway kit is included. In the event where the RV and vehicle separate, this unit will activate the vehicle's brakes, bringing it to a safe stop to prevent a runaway situation. The breakaway switch mounts to the front of the towed vehicle and gets connected to the RV with the included cable and clips. It wires into the operating unit, so if the car separates from the RV, the cable would be pulled, it would pull the pin from the switch causing a signal to be sent to the operating unit, and then a reserve air supply will then apply your towed vehicle's brakes bringing it to a safe stop. This system also features total coach protection and it's already built in, so if there is separation, the RV's air supply is going to be completely sealed off so its brakes will continue to function as normal. Again, necessary installation hardware and all necessary installation components are included with this kit.

The product's made in the USA. Last thing I want to do for you is simply just give you the dimensions right here of the operating unit. I'm just going to measure the box portion. The handles on the side are used for creating anchor points or installation points. The box itself measures about 8 and a half inches this direction, about 5 and three eighths to 5 and a half inches this direction, and when it comes to the thickness, that's bottom to top, it's only about an inch and a quarter thick. That's going to do it for today's look at the SMI Second Vehicle Kit for Air Forced One Supplemental Braking System.

Customer Reviews

SMI Second Vehicle Kit for Air Force One Supplemental Braking System - SM99209

Average Customer Rating:  4.9 out of 5 stars   (9 Customer Reviews)

Easily tow your other vehicle without having to install an entirely new SMI Air Force One supplemental braking system. Includes wiring, air lines and hardware.

- SM99209

Changed toad, so needed a second vehicle kit for Air Force One braking system. Delivery was as promised, packaging was very secure, and price was right. Will be installing soon. 606535

- SM99209

I had a few questions about the "Air Force One Second Vehicle Kit" and e-mailed them on Sunday. Monday morning I got a response and gave them a quick reply. Minutes later another quick response. The staff at E-Trailer went over and beyond with their knowledge and had all the answers. I ordered the kit Tuesday morning and was on my doorstep Thursday afternoon. Hats off to the "E-Trailer Staff" for the quick shipment. 596569

- SM99209

I installed this SMI Air Force One braking System on a 2017 Jeep Wrangler Sahara Unlimited. I watched and then followed the etrailer video. It was an easy install and the video was spot on. My coach already had the air tank installed, so I just had to buy the Second Vehicle Kit and the Air Jumper. 543135

- SM99209

All the items were exactly as anticipated and arrived when expected. etrailer sent me several emails keeping me appraised of the order status and to check that the package arrived ok. Excellent customer service. 485657

- SM99209

Excellent product. It's fairly easy to install if you're mechanically inclined. It is the best system to use on your toad if you have a diesel pusher. Installation difficulty is a 3 with 5 being the hardest. That's depending on what the model of vehicle it is being installed in. Great company. Their customer service is outstanding. 451973

- SM99209

Great product support and service 425895

- SM99209

Very satisfied with the order. Shipping was very quick. Everything was in order. One of the few retailers that advertised the SMI second vehicle kit. I wouldn't have known about it if I hadn't seen on their site. Saved me $300. Glad I bought from etrailer. Will buy from them again. 413254

- SM99209

Great job filling order. Great company to deal with! 400105

- SM99209

Ordered SMI Air Force One 2nd vehicle brake kit. I was concerned that it would not be the current model but was assured it would be after a quick. Product arrived quickly and was in fact the latest model. Price was great, service superb. Couldn't be happier. 385054


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Info for this part was:

Video by:
Andrew K
Expert Research:
Jameson C
Video by:
Joshua S
Video Edited:
Jacob T
Expert Research:
Adam R
Video by:
Kathleen M
Written by:
Laura H
Installed by:
Cole B
Photos by:
Sam P
Test Fit:
Randy B
Video Edited:
Chris R
Updated by:
Sarah W
Test Fit:
Andrew S
Updated by:
Jenny M
Photos by:
Jeffrey L
Test Fit:
Robert C
Updated by:
Kristina F

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