Alert !!!!/ Toad Air Brake Tn rally

[Ray Davis]

In thinking about what Jon said, I went to the SMI site to see if I could find ain installation guide.

I wasn't successful in that, but I did find a "plumbing" diagram.

It's not 100% clear, but it looks like they expect to tap into an air supply system AND then also to the brake.

I believe they show this on this diagram

http://www.smibrake.com/GetProductImage.aspx?ID=4

as "supply-air connection", and "metered-air connection".

I assume metered would be the brake lines, but I will admit to guessing here.


Ray

[0533]

Good morning All,

I have been traveling and am just now getting back online to look at these posts.

Here is what we found with the "Air Force One Air Brake" system. They mounted the Air tank, small version of the Prevost tanks and a valve near the D/S rear tag wheel up under the frame attached near the U shaped tunnel for the drivetrain shaft. When the Prevost leveling system was air was dumped the fitting between the Air Force One valve and the Air Force one tank caught on the corner of the Prevost frame and snapped of the valve at the fitting to the tank. The noise that I heard was the air in the tank evacuating. What I could not understand is why my main air was acting squirrely, not running up and dropping off quickly. I ended up having to replace my dryer in this process as it would not blow off at full pressure after this event. It might not be related but it was odd. The bottomline here is that the Prevost equipment and placement has been engineered carefully and with all of the potential pitfalls in mind. I am afraid that this is not the case with others, as there is not enough experience with our heavy complex units. Mine ran great out of jacksonville to San Antonio Fl. but I have to say that there is a large ????? mark in the back of my mind about the future, rocks, whatever. Hope I am wrong and am sure that the folks at Air Force One will be carefully looking into this and will report back to us online to give us a first hand assessment.

[0533]

I left out of Gainesville Fl. yesterday morning for the short ride back to Jupiter. The ride went smoothly (30 mph wind gusts). As we left 95 for the ramp into Jupiter I noticed a loud howling or squealing sound coming from the back of the bus. Nothing on the gauges showed me exactly what was going on but I knew it was not necessarily good.

I decided to get off the road and limp into my slip near home a few miles away.

The noise was deafening now and when I came to a stop next to my slip I noticed that both brake gauges were now at 80lbs. but holding there. I looked under the to see the same old line and valve hanging down next to the drive shaft air streaming out of the open end, plus the valve stem had been severed off at the threaded end.

I can not understand why this has happened again, there does not to appear to be a good reason for the failure twice in the same location.

I am not certain how to make temporary repairs at this time. want to stop the leak detach the lines to the Toad Brake valve and seal the main/Air force One Air tank leak so that my main brake air tank is not continually drained down by the demand on the open valve port on the Air Force One tank.

If my attachment has been uploaded you will see where the problem is.

I want to get under the bus to examine this better, plan on tilting the airbags over to one side, placing the Prevost Jack on the high side for safety and then detach the dangling valve, and try and screw into the Airforce One Air tank some type of threaded screw to seal the hole, any ideas.

[0533]

I left out of Gainesville Fl. yesterday morning for the short ride back to Jupiter. The ride went smoothly (30 mph wind gusts). As we left 95 for the ramp into Jupiter I noticed a loud howling or squealing sound coming from the back of the bus. Nothing on the gauges showed me exactly what was going on but I knew it was not necessarily good.

I decided to get off the road and limp into my slip near home a few miles away.

The noise was deafening now and when I came to a stop next to my slip I noticed that both brake gauges were now at 80lbs. but holding there. I looked under the to see the same old line and valve hanging down next to the drive shaft air streaming out of the open end, plus the valve stem had been severed off at the threaded end.

I can not understand why this has happened again, there does not to appear to be a good reason for the failure twice in the same location.

I am not certain how to make temporary repairs at this time. want to stop the leak detach the lines to the Toad Brake valve and seal the main/Air force One Air tank leak so that my main brake air tank is not continually drained down by the demand on the open valve port on the Air Force One tank.

If my attachment has been uploaded you will see where the problem is.

I want to get under the bus to examine this better, plan on tilting the airbags over to one side, placing the Prevost Jack on the high side for safety and then detach the dangling valve, and try and screw into the Airforce One Air tank some type of threaded screw to seal the hole, any ideas.

I appear to be having problems attaching the pics for better assessment. I will continue to try.

[JIM CHALOUPKA]

Bruce, not sure how many lines you have to cap off, but for the short term if you can get to them use vise grip pliers to crimp the end to get you to somewhere where you want to do the permanent fix.
Sometimes you have to bend the line over and hold it there.
If you carry ss lock wire and you have more leaks than pliers, fold over the line and secure it with lock wire, and wrap with tape. A tiny leak will probably be tolerable.
Good luck and keep us posted
JIM

[0533]

Bruce, not sure how many lines you have to cap off, but for the short term if you can get to them use vise grip pliers to crimp the end to get you to somewhere where you want to do the permanent fix.
Sometimes you have to bend the line over and hold it there.
If you carry ss lock wire and you have more leaks than pliers, fold over the line and secure it with lock wire, and wrap with tape. A tiny leak will probably be tolerable.
Good luck and keep us posted
JIM

Thanks Jim,

I will try this as a short term fix. I plan on heading up to Prevost for some other regular service and this might make it easier than trying to go all the way with a complete fix as I really need to get a handle on why this has happened twice now, and how to find a way to make sure it will not reoccur.

I wanted to attach a few pics that might offer some insight, but each time I try and upload an image file Gif 570KB the POG. server will not respond, both in Safari and in Firefox, wonder if others are having this problem??

[Jon Wehrenberg]

Bruce,

Don't worry about pictures for us until you and the coach get to safety.

I will assume these problems with the braking system are isolated, but for anybody that has one of these systems I would strongly urge before you travel with your coach to add a 90 degree shutoff valve (ball valve) in the supply line to the braking system air supplies. Then no matter if you get a broken fitting or a defect in the device all you need to do is get access to the valve and shut it off. Then you can deal with the leak on your own terms.

Think of the valve the same way you would a circuit breaker. It is just there in case you have to shut down the system for service.

[Alek&Lucia]

Bruce,

Try to save your photos as JPEG it should work better.

Alek

[0533]

Bruce,

Don't worry about pictures for us until you and the coach get to safety.

I will assume these problems with the braking system are isolated, but for anybody that has one of these systems I would strongly urge before you travel with your coach to add a 90 degree shutoff valve (ball valve) in the supply line to the braking system air supplies. Then no matter if you get a broken fitting or a defect in the device all you need to do is get access to the valve and shut it off. Then you can deal with the leak on your own terms.

Think of the valve the same way you would a circuit breaker. It is just there in case you have to shut down the system for service.

Good idea Jon.

I am confused why this is happening. The last time the valve was pinched by the top of the drivetrain well when I was using my auto leveling.

This time I was simply driving along and it gave way.

I am not pleased with the experience and need to find a better way to have this entire system installed as I believe it will happen again.

It appears when they tap the air off of the main system there is no fail safe built in to protect the braking system in the event of a failure.

[Jim Skiff]

I spoke with Peter in Minnesota and he has re-engineered the product. He also appears to be very responsive to POG issues related to Air Force One.

I'll see if he can respond here.