SMI airforce one question

[S-n-L]

Hello everyone,

I am thinking of the SMI airforce one however I have spoken to two RV dealers about instillation and both of them told me that they do not recommend any braking system that taps in the coaches air supply.

Both of these dealers are in the Albany, NY area. I wonder if there is some regional lack of knowledge on this product.

I would like to get some input on this.

Thanks,

Stuart

[wil01]

The Air Force One is the only air operated system that Spartan approves. The system was designed with input from Spartan and Bendix. A call to Spartan can verify this.

I have it on my country Star and it is marvelous.

god Luck1
Wil

[WesinRockies]

I did mine just last month it wasn't bad at all to do. Shop wanted 6 hours of labor to do it. It probably took me a bit longer to do but I did a few upgrades to it. Would I do it again myself? Yes I would!

[Abclipper]

Hi Stuart

We have the Air Force one system on our MH and before we installed the system we had heard of the issue that you should not break into the coaches air system but we talked to a few people with this system and went online and watch the SMI video and all were very positive answers and no issues, now we have it and it works great we would never have any thing else easy to hook up and disconnect also, so if you have not checked with others and watched the SMI video I suggest you do.
The one thing we did extra was wire up the brake application light to the dash so we can see when the toad brakes are applied. Hope this helps.

[C&SL]

Our work great!! No problems.

[RV735]

We have had ours for 3-1/2 years and 25K miles of towing with no problems. It is as simple as attaching the quick connect air hose from the RV to the toad. The brake lights on the toad are activated automatically. We use the Airforce one brake system with a Blue Ox 10K tow bar. Both very simple to use and store.

Safe travels and THE JOY IS IN THE RIDE

[Pigman1]

Ditto on all the comments. We have had the same system on 3 class A's and thru 2 different toads. Well over 150,000 tow miles on it and wouldn't have a different setup. By the way, the AF1 is the only system on the market that meets Federal Motor Vehicle Safety Standards. These boys and girls got it right!!!!

[waroland]

I installed mine about a year ago. Not real hard and works great. No box to keep up with or settings to figure out. It just follows what the coach brakes are doing. I love it!

[ImagineIF]

Find another dealer! I have had my AF1 on 2 coaches and just on 2 different TOADs. As far as I know the AF1 and M&G system are the only ones that truely provide prortional braking and both use the coach's air system. FWIW, the M&G system won't fit on many TOADs.

AF1, money well spent.

[S-n-L]

Thank you all for your responses. We have lots of great info.

Stuart

[smlranger]

We had our AF1 installed on a Winnebago Journey and it worked flawlessly for 6 years. Traded rigs and had it moved to the Country Coach Allure. The dealer did add a kit that included a small air reservoir on the Allure but not sure that was absolutely necessary but they insisted it was necessary to safely tap into the coach's air system.

Suggest you give the folks at SMI a call with any technical questions. They are very helpful.

[phays]

I'm now on my second coach with the Air Force One and have had no problems. About two years ago I ran over a tire tread that took out my electrical connections and the AFO air line to my toad. Although the airline was ruptured, I could not detect a leak in the air system and saw no decrease in air pressure in the coach. There is a solenoid valve on the toad air supply line from the coach that closes if there is a problem with the toad.

[TVforMyRV]

Way back in 2008, I wrote up a description of the AF1 system and how it integrates in your coaches air system. It stills remains a valid explanation of the "safety" apect of the AF1.


I just installed the newly revised Air Force One system two weeks ago. I say newly revised, because in late 2007 SMI released a new version of the AF1 which I believe to be far easier to install, and with fewer potential problem points.

There are now two reserve air tanks, one in the coach and one inside the toad controller to provide break-away protection. The 4-wire electrical connection between the coach and the toad is eliminated, as well as the electrical control box in the coach. The ONLY connection between the coach and the toad is, the 1/4" air line, and the break-away safety cable.

There has been some discussion about the "safety issues" involved with "cutting into" the coach air system. Well, I would say in 98% of the cases, you really don't have to "cut" any lines on the coach if you don't want to. It's just that it is usually easier to to access the plastic lines at the rear of the coach and "T" into them rather than find an appropriate threaded connection to "T" into.

COACH PROTECTION
The same "protection" valves that are used by the chassis manufacturers to provide dual, redundant, and independant brake systems, is used by SMI as the "input" to the SMI supply air tank. This valve will not open unless there is at least 60-70 PSI on the Coach supply side of the system. If a catastrophic failure were to occur between the coach and the toad, this protection valve would "protect" the coach supply by closing at approximately 60PSI. Now you say, what about the line from the coach air supply INTO the SMI valve? Well, that is now protected by whatever device or redundancy the manufacturer installed in the chassis the same that the air line was protected before you "T'd" into it. I really see no need for concern about "cutting into" the coach air system, and SMI specifically states that their system is approved by Spartan, and meets all applicable Federal Saftey requirements.

You could really think of the SMI AF1 system this way. Instead of TWO seperate and redundant braking system (front and rear axles), you now have THREE air brake systems front, rear and toad, each protected by it's own protection valve.

METERED AIR
This is the "air signal" generated by the treadle valve (foot valve) when you step on the brake pedal. This air signal is then "relayed" to the front and rear brake systems by a valve that essentially works like an air pressure controlled regulator. The air from your foot valve does not actually go to the brake chambers, it feeds/controls the relay vavles which in turn allow air to go from the tanks to the brake chambers proportionally to the amount of air pressure from the foot valve. The second air connetion from the coach to the SMI system is a "metered air" line which "relays" the foot valve air pressure to the toad, via a "relay" valve which is supplied by the SMI system air tank mounted on the coach. This connection can be either a "T" into an existing metered air line, or, simply remove one of the threaded plugs from one of the unused ports, in one of the coach relay valves and use that port to supply metered air to the SMI relay valve. You will most likely find these lines referred to as "service" (input to relay valve) and "delivery" (output from relay valve). The end result is that when you press the foot pedal, that air pressure signal is propogated to each of the air brake systems, front, rear, and toad, which supply air to the brake chambers and apply the brakes.

TOAD INSTALLATION
The installation in the toad is technically straight forward, just a pain in the rear sometimes to figure out where you are going to put things, and how you are going to get through the firewall, and how to find/access the brake light switch under the dash. These jobs were so much easier when I was more limber, flexible, and did not need bi-focals to see what I was doing......

The air line jumper between the coach and toad supplies air to the SMI control box when the foot pedal is pressed. The control box has a small, built in reserve tank which is used to apply the toad brakes when the break-away switch is activated. The control box also generates vacuum to the brake booster, using the coach air to drive a vacuum ejector. This allows the activating cylinder mounted on the toad brake pedal to be quite small, and still provide plenty of brake pressure to the toad brakes by utilizing the booster system in the toad. All vacuum tubing, the check valve, and potential usable tubing adapters are included with the SMI AF1 kit. There is one electrical connection between the SMI unit and the toad and this is a 12V supply going through the break-away switch. They provide an external fuse holder with a pig-tail long enough for most any situation. I simply connected the pig-tail to an empy block in the distribution box which provided unswitched 12V. When the break-away switch is pulled this signals the SMI control unit to apply the "emergency brake". It is important that this is attached to an unswitched voltage source, since this needs t have voltage at all times when being towed.

In the previous version of AF1, you had to install a "notification light" in the cockpit of the coach, which is turned on when the toad brake pedal is depressed far enough to turn on the brake lights in the toad. This provided you with a visual confirmation that when you pressed the pedal in the coach, that the brake pedal in the toad was also depressed at least far enough to turn on the brake lights. There is still a "coach notification light", but now it is a high intensity LED light assembley that they suggest to be mounted to the tow bar (via Velcro) in a location that is visible in the rear view camera. Although I like the simplicity of this idea, I didn't really find what I considered a suitable location on my Blue Ox towbar to attach the little LED assembly. Instead I simply attached it to the front bumper of the Jeep Liberty and unless I find some reason to move it, I'm going to leave it on the bumper right above the air line, auxiliary brake/turn signal connector, and break-away switch. Everything "towed" related is nice and neat and tidy looking and all in one area that way.

TESTING
Checking it out in the driveway after the installation was all complete was very gratifying. Everything worked as it was supposed to, and I was pleasantly supprised at the responsiveness of the toad brake pedal when applying the coach brakes at different foot pressures. I had the DW operate the foot pedal in the coach, from my instructions via the radio, and the Jeep brake pedal moved in and out as I instructed her to apply, apply harder, apply less, etc. I was amazed at how fast the Jeep pedal responded to changes in brake pressure.


ACTUAL USE
Our first road trip was 480 miles (round trip) to the FMCA GEAR rally in Richmond, VA last week. I guess I can only sum it up by saying that as far as brakes were concerned, you didn't even know the toad was back there. The notification light came on quickly when I applied the brakes and went back off when I released the brakes.

MINOR COMPLAINT
If I were to say anything negative at all, it would be simply that the LED assembley should be supplied in a matte finish, instead of a "chrome" finish. In bright sunlight, the chrome finish reflects enough light, that in the camera, it can look like the notification light is "on" even when it is really "off".

I would highly recommend the SMI Air Force One system for anyone who has an air brake equipped coach and want to have a state of the art braking system with break-away protection.


Don Sweger

[ImagineIF]

I installed a small, maybe 4", LED light strip on the lower part of the TOADs windshield. The LEDs are bright blue and easily seen in the coach's rear view camera.