Just Installed SMI AIR FORCE ONE Brakes

[Dutch Star Don]

I wrangled with what brake unit to install on my coach. Asked for advice here and read the literature on all of the systems several times. I was leery of tapping into my air brake system with the SMI Air Force One, but I took the leap.

I just purchased a new 2007 Dodge Dakota 4WD Automatic and will use it as my towed. I ordered the Roadmaster Sterling tow bar and brackets and the SMI system on-line. When the SMI system arrived I looked around the engine compartment for a spot for the main unit (a box approx 10" x 3" x 4") and a 8" x 3" reserve air tank. Amazingly enough the Dakota, which has a V-8, had literally no room under the hood for the above two items.

TOWED INSTALL - I decided to install the tow bar base plates first and discovered a ton of protected room behind the front bumper (cavity) to place the SMI components. I was able to do a very clean install of the two main components in the cavity which kept the air hoses and wiring close to each other.

The SMI uses a small 1" x 4" cylinder that attaches to the brake pedal arm and then has a vinyl coated cable that bolts to the floorboard for the cylinder to pull on. The only thing I didn't like was the self taping screw that holds the cable holder to the floorboard. It wouldn't tighten because of the thin metal so I through bolted the hold down. This hold down is what the brake pedal pulls against. I felt more comfortable with the through bolt and large washer.

Once the components were installed the wiring and air line plumbing was very simple. Your brake booster line gets a Tee that runs to the main control box.

COACH INSTALL - Installing the fittings for tapping into the air brakes were a lot easier than I expected. I unscrewed the the airline on one of the treadles (tanks on rear end) and inserted the fittings. All of the airlines snap into the supplied fittings. I ran the airline to the rear of the coach (inside plastic wire protection) and connected to the small SMI breakaway box. The box has one lead that goes to ground, one to a keyed ignition and one optional line for a dash mounted indicator light.

I'm VERY anal about clean installations and the tow bar, brakes and vehicle lights (4 lead wire to diodes at the rear of the Dakota) took me two full days to install.

TEST DRIVE - I hooked everything up today and had the DW watch that all of the lights worked properly and then tested the brakes. She was able to watch the Dakota brake pedal being depressed proportionately as I stepped on the coach brakes. Everything worked very well. With the whole system mounted behind the bumper, I was able to put the 6 lead Roadmaster trailer light cable, the SMI 4 lead wire harness, air hose and break away cable in a crossbar, just in front of the radiator. There all hidden behind the grill and when connected the hose and wiring comes out the front of the truck between the bottom of the grill and bumper.

The test drive went well, but I found that the Roadmaster trailer lighting cable was a few inches too short on turns. Monaco locates their trailer connector on the driver's side of the coach, at a weird angle, and too far back. I'll move the bracket tomorrow.

Finally, SMI has a breakaway system that does two things. First, if the towed breaks away the box installed on the rear of the coach shuts off the air so the coach doesn't have an open air line. Second, the towed uses the installed reserve air tank to provide air and apply the towed brakes. Once I was done with the road test I pulled the breakaway cable and tested the breakaway system. The towed brakes applied themselves and stayed on.

This was a lot of work, but I love projects like this and feel better when I can install something myself and know how it functions and how to fix it if it breaks. The instructions were okay, but could have been better. The quality of the kit was very good with all the necessary parts with the exception of the plastic wire protection that could have been supplied for the price.

I hope this helps someone with making a decision on what system and if they are willing to try the install. If you're handy the project will take a FULL weekend to do a nice job.

[Dutch Star Don]

I wrangled with what brake unit to install on my coach. Asked for advice here and read the literature on all of the systems several times. I was leery of tapping into my air brake system with the SMI Air Force One, but I took the leap.

I just purchased a new 2007 Dodge Dakota 4WD Automatic and will use it as my towed. I ordered the Roadmaster Sterling tow bar and brackets and the SMI system on-line. When the SMI system arrived I looked around the engine compartment for a spot for the main unit (a box approx 10" x 3" x 4") and a 8" x 3" reserve air tank. Amazingly enough the Dakota, which has a V-8, had literally no room under the hood for the above two items.

TOWED INSTALL - I decided to install the tow bar base plates first and discovered a ton of protected room behind the front bumper (cavity) to place the SMI components. I was able to do a very clean install of the two main components in the cavity which kept the air hoses and wiring close to each other.

The SMI uses a small 1" x 4" cylinder that attaches to the brake pedal arm and then has a vinyl coated cable that bolts to the floorboard for the cylinder to pull on. The only thing I didn't like was the self taping screw that holds the cable holder to the floorboard. It wouldn't tighten because of the thin metal so I through bolted the hold down. This hold down is what the brake pedal pulls against. I felt more comfortable with the through bolt and large washer.

Once the components were installed the wiring and air line plumbing was very simple. Your brake booster line gets a Tee that runs to the main control box.

COACH INSTALL - Installing the fittings for tapping into the air brakes were a lot easier than I expected. I unscrewed the the airline on one of the treadles (tanks on rear end) and inserted the fittings. All of the airlines snap into the supplied fittings. I ran the airline to the rear of the coach (inside plastic wire protection) and connected to the small SMI breakaway box. The box has one lead that goes to ground, one to a keyed ignition and one optional line for a dash mounted indicator light.

I'm VERY anal about clean installations and the tow bar, brakes and vehicle lights (4 lead wire to diodes at the rear of the Dakota) took me two full days to install.

TEST DRIVE - I hooked everything up today and had the DW watch that all of the lights worked properly and then tested the brakes. She was able to watch the Dakota brake pedal being depressed proportionately as I stepped on the coach brakes. Everything worked very well. With the whole system mounted behind the bumper, I was able to put the 6 lead Roadmaster trailer light cable, the SMI 4 lead wire harness, air hose and break away cable in a crossbar, just in front of the radiator. There all hidden behind the grill and when connected the hose and wiring comes out the front of the truck between the bottom of the grill and bumper.

The test drive went well, but I found that the Roadmaster trailer lighting cable was a few inches too short on turns. Monaco locates their trailer connector on the driver's side of the coach, at a weird angle, and too far back. I'll move the bracket tomorrow.

Finally, SMI has a breakaway system that does two things. First, if the towed breaks away the box installed on the rear of the coach shuts off the air so the coach doesn't have an open air line. Second, the towed uses the installed reserve air tank to provide air and apply the towed brakes. Once I was done with the road test I pulled the breakaway cable and tested the breakaway system. The towed brakes applied themselves and stayed on.

This was a lot of work, but I love projects like this and feel better when I can install something myself and know how it functions and how to fix it if it breaks. The instructions were okay, but could have been better. The quality of the kit was very good with all the necessary parts with the exception of the plastic wire protection that could have been supplied for the price.

I hope this helps someone with making a decision on what system and if they are willing to try the install. If you're handy the project will take a FULL weekend to do a nice job.

[MonacoMama]

Good goin'... Dip D...glad to hear you were able to get stuff set up to your liking! I am sure you always feel as satisfied as Sacs does when he gets a project like that completed.

BTW..where are your photos?

[Dutch Star Don]

In my camera!

[MonacoMama]

Ahemm...
You do know where to email them don't you?

[ronboc]

Great installation job and a superb write-up, Don. Not only do you get peace-of-mind from doing the job right, you also get the added feeling of safety and control when stopping.

Thanks!
Ron

[BIGRED1]

Dip Don, how difficult was it to install the "trailer wiring" and diodes on your Dakota? Was it "just" a matter of finding the correct wires in the taillight assembly on the towed to splice into? Are the diodes in-line in the wiring going from the towed to the wiring plug on the coach? How many diodes were required and on which wires?

TIA!!

[ronboc]

I'm sure Don will pop in with his Dakota job, but I gotta 'brag' about me doing my '06 Dodge Minivan.

After spending an entire day tracing-out and soldering wire after wire at the rear of the van to get it all connected properly, I happened to look in the manual to double-check something. Lo and behold, there was a picture of where to find the integrated trailer-wiring harness plug! Doh!

Reason I bring it up is hoping maybe other folks won't have to kick themselves like I did.

Ron

[Jestme13]

LMAO @ Ron, I thought only I did stuff like that. I'm getting ready to install the base plates and diode system to the new HHR. I'm not looking forward to it

I am also debating the air force one system, D Don how did you think the braking system felt ? I have an Apollo system that works OK.

[Dutch Star Don]

BIGRED1 and Justme13....The wiring of the diodes was a snap. If your brake light and turn signal are the same bulb you'll need five diodes. The kits come with two, three or five diodes in them. I think the easiest way to wire them is the way I did it. I bought a 25' roll of the grn/brn/yel/whi wire for trailer wiring and ran it the length of the vehicle along the frame.

I pulled the right rear lens and removed the bulb/socket. On the Dodge there are three wires running into the socket. One for the turn signal/brakes, one for the running lights and one for ground. On the turn signal wire you cut it where you can get at both ends of the cut wire and put a female wire connector (spade type) on both ends of the wire you just cut. You put a female spade on the green wire you ran along the frame. You now have three female spades. The diode comes with two "IN" male spades and one "OUT" male spade.

The green wire that you ran from the front of the car (which will eventually have power running down it from the coach) and the wire you cut (the end coming from the front of the car that supplies power to the turn/brakes) go into the two "IN" spades. The wire that you cut that is still attached to the bulb goes to the single spade marked "OUT". If you can picture it, power coming from your coach wiring or power coming from your vehicle wiring both enter the diode and come out at the single out spade. The diode blocks the two power sources (coach and vehicle) from running back the wrong way in the lines.

I ran the yellow wire to the left side and I split the brown tail light wire so that it went to both sides. I used the fifth diode to make the license plate lights work. I tapped into the brown wire where it ran across the bumper from the left to te right and ran a wire down to a diode and into the license plate lights.

I hope I don't insult anyone on how the diodes work, but once I understood the concept of the two power sources in and a single power out to the bulb it made wiring them very easy. I think on some vehicles you could tap into the tail light wiring in the front of the car, but you would have to identify all of the color coded wires and then trace them back.

Jestme13....I'm sure most of the brake systems are fairly proportional, but it's neat to watch the towed pedal go down as the coach pedal is depressed. You can also put a little more or little less slack in the wire that attaches to the brake pedal and make the towed come on sooner or later. The break away system is nice too. You can have the car parked away from the coach and pull the break away cable and the brakes will apply and stay applied until you put the break away plug back into the box.

[MonacoMama]

OK... Can I just point out Dip Don's list of modifications posted here on the Monaco board far outnumber the standard features on the coach! He and a few others (including you, Sacs! ) have that knack of doing whatever they want to do with an easy manner about it.
If you are not one of those really handy people...then know that this job will not be just a simple weekend job without the help of that neighbor who you see out there rewiring the whole neighborhood!

[Jestme13]

Thanks D Don, I bought the Blue Ox wiring system with the block Diode. It looks fairly simple, just a matter of running the wires, like you I will run them underneith the car and come up in the rear.