Community Forums

NealC · 06-25-2017, 09:09 AM

I have a new coach and my dealer installed the SMI Air Force One prior to taking delivery of the coach. I took the coach to SMI and they did the coach side install of the Air Force One. After I got back to Virginia I noticed the cable to the solenoid was extremely slack so I got an allen wrench after reviewing the installation guide from SMI and tighted it to have 1/4 to 1/2" slack.

I've had problems with the red light remained on, the reed switch popped out. I don't care about the red light, I really can't see it from the coach and I'm not sure it's working properly and it's not really going to tell me that sufficient braking is being applied I suppose. What I do care about is whether the brakes are being applied when I'm braking the coach AND is it sufficient or too much braking? The brake pedal in my toad is a bit hard to press compared to my Honda Pilot, it's a new 2017 Chevy Colorado. I'm not sure how the SMI AF1 knows how much braking to apply.

As I'm a solo RV'er I'll probably turn my iPhone video on and test from the coach side and see that the brake pedal is moving. That will be my first vote of confidence. But how do others know the braking system is doing what it's designed to do. I guess I should pull the emergency disconnect as a test as well and see that the toad cannot roll forward.

I have not felt a different with or without the AF1. I towed (don't tell anyone) from Newmar to SMI without the coach side installed yet and braking was fine. But noticed no difference after that but not sure I will. I just need confidence this very expensive braking setup is actually doing what it's supposed to do. Beyond the red light, which I don't have confidence in, how do you know all is well with the toad braking?

Spk64 · 06-25-2017, 09:26 AM

I have tested my setup in 3 different ways. Solo might make it harder with some methods.
1st is to just connect an air compressor to front and see if brakes are locked.
2nd is watching it while someone depresses brakes
3rd after coach running and depressing brakes a few times. Pull the breakaway. See if brakes locked up.

Where you will really appreciate it is in an emergency where you need maximum braking. We were really close to rear ending a car when we approached stopped traffic on a highway. Was surprised how quick and short a distance we stopped.

DrDaveMA · 06-25-2017, 02:50 PM

I have the SMI DUO but it works the same way as the AF1. In the morning after I have hooked up the toad, when I do my light check I put on the 4 way flashers, that way I know the brake lights and 4 ways are working on the toad, then go to the brake force adjuster and decrease it until the SMI engages the brakes, I let it activate them for 2 or 3 cycles then increase the sensitivity until the brakes stop activating and tighten the knob. This tests the wiring from the coach through the tow cable as well as the SMI unit, proving that all is working. Pulling the breakaway switch does a similar test but it does not tell you your brake light system is working or activating the SMI.

Dutch Star Don · 06-25-2017, 04:29 PM

"NealC".....Over the years, I've owned three generations of the SMI units and have installed it on two coaches, four trucks and one CRV. I ALWAYS run a wire to the cab and install a light on the dash. The minute the brake pedal moves, the light comes on. This is nice to test the system after I connect.

The only real adjustment you can do to the system is to adjust the cable length like you did. I like having just a smidge of slack. This worked well on all four trucks. I bought a Honda CRV for a coast to coast trip and installed the system on it. I noticed after a few days of towing, there was excessive brake dust on the front wheels. The light was also coming on with any application of the brakes. I loosened the cable and the issue was resolved.

Here is something I've always changed regarding SMI's install method. When they attach the cable to the brake pedal piston, they attach the other end to the floorboard with a self tapping screw. I always drill it through and use a bolt and nut. On the CRV, I couldn't do that, so I made a bracket that bolted to some existing bolts and connected the cable there I just don't trust the self tapping screw.

cruzbill · 06-25-2017, 04:35 PM

When you stop the coach, check to see if the front brake rotors are warm / hot on the toad......

Spk64 · 06-25-2017, 06:07 PM

Quote:

Originally Posted by Dutch Star Don

"NealC".....Over the years, I've owned three generations of the SMI units and have installed it on two coaches, four trucks and one CRV. I ALWAYS run a wire to the cab and install a light on the dash. The minute the brake pedal moves, the light comes on. This is nice to test the system after I connect.

The only real adjustment you can do to the system is to adjust the cable length like you did. I like having just a smidge of slack. This worked well on all four trucks. I bought a Honda CRV for a coast to coast trip and installed the system on it. I noticed after a few days of towing, there was excessive brake dust on the front wheels. The light was also coming on with any application of the brakes. I loosened the cable and the issue was resolved.

Here is something I've always changed regarding SMI's install method. When they attach the cable to the brake pedal piston, they attach the other end to the floorboard with a self tapping screw. I always drill it through and use a bolt and nut. On the CRV, I couldn't do that, so I made a bracket that bolted to some existing bolts and connected the cable there I just don't trust the self tapping screw.

I did the same on our install. Put a thru bolt for the cable to attach to.

phays · 06-25-2017, 06:28 PM

I'm a single RV'er and check my AFO several ways. The simplest is to get a stick long enough to press the brake pedal on the coach when jammed against the steering wheel. Then go check to see if the toad brake pedal is depressed and if the toad brake lights are on.

My AFO is a 2007 version and at that time a wire connected to the toad brake pedal switch was pulled to the coach dash. I have a light on the dash that goes on when the brake pedal switch in the coach is depressed and the toad pedal goes down.

Don't know what you mean when you say a cable connected the solenoid. Are you saying the cable from the air cylinder to the toad brake pedal?

I know of no way to check the braking force from the toad brake pedal being depressed by the AFO. I do know if you forget to put the dummy plug in the break away switch and try to drive the toad you will notice that the brake pedal is depressed quite a bit and might keep you from moving the toad without excessive pressure on the gas pedal.

mhudson · 06-25-2017, 06:34 PM

If you have adjustable pedals in the toad make sure that the pedals are all the way out (rearward toward the seat) when you adjust the cable slack. If they aren't there is a chance of the brakes dragging if someone adjusts the pedals out later driving the car. You will need to make sure that you adjust the pedals to the full outward position when towing. The company that did the install on the toad may have done this and later the pedals were adjusted toward the firewall which would cause the cable to have extra slack. This would be normal.

Dutch Star Don · 06-25-2017, 10:45 PM

Yes.....there is a steel cable that runs from the air cylinder (mounted on the brake pedal) to the floorboard of the toad. This cable can be adjusted. If too slack, the brakes won't come on. If too tight they will come on too soon.