Alert !!!!/ Toad Air Brake Tn rally

[0533]

Bruce,

First, let me say that I regret you seem to be having repetitive problems with your AFO Supplemental Braking system.

Second, I must also say that I have had excellent response to my communications with Peter Schenk, owner of SMI. In fact, we had told him of a possibility of being through Evansville in late June or early July. Our travel plans changed to where we would not have been going through Evansville. On the morning we were eastbound leaving Kansas City Peter called me to find out when he could expect me to be in Evansville for him to check my AFO installation and if necessary, install a new unit. We revised our travel plans to go to Evansville and have Peter check our unit. Turned out the unit was fine and I did not need a replacement. I did however inquire as to why I was killing batteries in my towed vehicle. Well when the towed brake pedal is pulled down by the AFO unit to apply towed vehicle brakes, my towed's factory brake lights come on also. Peter devised a cutout relay that takes the factory brake lights out of the equation when the AFO is active. No further problem with the battery. This modification was performed at no cost.

So finally let me say that communication is a two way street. It might be more beneficial to you and other POG members, to simply pick up your phone and give Peter a call. Here is their 800 number from their website which has a link directly from the POG opening page.

1-800-893-3763

Now for a little background information. Prior to purchasing a towed braking system I posted a question on the POG forum about towed braking systems. I did not care to have another device to install and remove from the towed vehicle. Yes, I researched M&G but they do/did not make a unit for my towed vehicle. They say there is no room under my towed's hood for their unit. I got feedback from Lew and he had an AFO in a Saturn towed with which he was satisfied. Now Lew just does not go spreading Lewbucks everywhere so I thought maybe there is something I can get done with an AFO unit. I got in touch with Peter before the Sevierville Rally and he was willing to come to the rally to do my installation and use my installation as a seminar for the rally. It was not his intention to sell everyone a system since he only brought two with him. He had to get other units shipped in to meet the numerous POG member requests for installations on their towed vehicles.

I think you said earlier that a Prevost shop did the upgrade following the first failure. If the location of the installation was a problem it seems to me as if they could have moved the unit with little effort and there would be no need for this discussion.

Again, I regret you are having this problem, I am joyous that there was not a safety consequence, and I am certain that Peter Schenk will stand behind his product.

I do hope you get a permanent fix for your problem this time around.

I like you am sure that Peter will stand behind his system, and in no way feel that he will not.

I have emailed Peter all the necessary info to start his investigation and hope that he has a plan for a better install.

As for Prevost Jacksonville, they simply reinstalled the old part back onto the tank etc. They did move the valve and lines away from the driveshaft well so it would not come in contact with the shaft, but in no way did they re-engineer the install or get any direction from Peter (to the best of my knowledge) on what was needed to make the repair. It was done as a courtesy to me and to help get me back on the road.

I think it is great to have a strong working relationship with Peter, and am still pleased that we were introduced to Peter and his product, but all of this does change the fact that the system needs major improvements to be worthy of an install on our buses.

I plan on sticking it out with Peter in hopes that we can all have the kind of result we had expected in the first place.

I am sure that Peter will keep all of us informed on his plans.

As I have stated in our responses, my bus is like yours, but possibly I have been out there using it more than some, not sure, just feel that if each of you are not fully aware than the end result might not be the correct one.

[lewpopp]

I am embarrassed to say that the AFO I presently have is not the original set-up that was installed by one of Peter's "authorized" shops.

It was a Stay-N-Play and wasn't worth a s-it. Peter agreed with me and said it should never have been put on the Prevost.

I went to another "authorized" AFO shop and they changed a lot of things out and Peter supplied the changed equipment.

Needless to say I was out another $550 bucks for the labor of which I was not the slightest bit happy. I presently have over $2100 Lewbucks in this and I'm still not satisfied and now I'm scared about it's performance.

I do not have an airtank in my system (why?) and my airline runs directly from my service line at a brake chamber. The installer said the coach could make up much more than the air lost if it should break loose so that should not be a problem.

Peter, you can expect my call soon.

I had mine installed after the Sevierville rally. I did not have nor did I say I had an AFO and I was misunderstood. I'm sure we could look up what I said in response to the question of the system I had. Perhaps I made the response over the e-mail

[0533]

I am embarrassed to say that the AFO I presently have is not the original set-up that was installed by one of Peter's "authorized" shops.

It was a Stay-N-Play and wasn't worth a s-it. Peter agreed with me and said it should never have been put on the Prevost.

I went to another "authorized" AFO shop and they changed a lot of things out and Peter supplied the changed equipment.

Needless to say I was out another $550 bucks for the labor of which I was not the slightest bit happy. I presently have over $2100 Lewbucks in this and I'm still not satisfied and now I'm scared about it's performance.

I do not have an airtank in my system (why?) and my airline runs directly from my service line at a brake chamber. The installer said the coach could make up much more than the air lost if it should break loose so that should not be a problem.

Peter, you can expect my call soon.

I had mine installed after the Sevierville rally. I did not have nor did I say I had an AFO and I was misunderstood. I'm sure we could look up what I said in response to the question of the system I had. Perhaps I made the response over the e-mail

I have had a good conversation with Brent from AFO. Brent has explained to me what has been going on with the AFO systems installed on our buses.

First Brent explained that they have discovered that the vibration (harmonic) that somehow gets setup under the bus while driving down the road has been the source of the problem.

There was a connection between the tank and the valve (nipple). This nipple was in fact the point of connection and was the point at which all forces were applied.

I think that Brent and Peter have taken a long look at their Prevost installs and now realize that thy were not engineered well for our buses.

In my case Brent has or is about to send along the new improved version of the product to his trusted Orlando Dealer for install in my bus.

It is an interesting process following the progression of this product and its evolution.

In my case when the parts vibrated the nipple off it actually caused the entire install to come apart including having the tank break away from its bracket/secured location and fall back behind the bus striking the toad.

I have stated this before in this thread, but feel it is worth mentioning it again and even expanding this discussion to recap what has been accomplished as a result of threads like this one.

By bringing these problems to light and sharing them with experienced Prevost owners in this thread, we have been able to troubleshoot Peters problem, possibly saving Peter time and even reducing future liability that could have been the consequence of future failures.

I think that Jon nailed the problem when he stated that the install needs to be made hard to the Prevost frame, and that this must be part of the overall product installation program. I also believe that as Jon said there needs to be an inline shout off in the event of a failure.

I know how important it is to create a product that is price competitive and good and realize that adding these additional steps will increase the overall cost, but am certain that the extra hour of install time and the inline shut off will be well worth the expense.

In my case I plan on making sure that not only are the new and improved parts installed but (based on the fact that all of my components vibrated off the bus) that I get the 1. the location carefully inspected for best result 2. That the parts are carefully secured to the bus frame 3. That a shutoff is placed inline.

I have owned like you guys lots of stuff, and have been the guinea pig in more than one time including aircraft and boats, from crappers to fuel injection and feel that in this case we can actually work with Peter and his team to help him (and ourselves) improve and make his good idea a truly better mousetrap.

[Jon Wehrenberg]

The locations have the potential to vary because the buses vary. Prevost has evolved the buses to the point at which later models have accumulator tanks plumbed directly to the air bags. Those tanks occupy space that would be great for the braking system. So earlier models (early "T" and prior) would have plenty of room, but on later models it may be a challenge.

What Peter needs as a manufacturer is to see a variety of coaches and find the spot that is universal to all of them so he has a standard "Prevost" product. Once he has that place selected then the devlopment of attachments and connections and subsequent testing can take place. I strongly suspect that if the relay valve and tank are secured properly, and all connections to those devices have at least a short flexible section these problems now being encountered go away forever.

He cannot count on spaces in the engine compartment because converters use that space differently and the only area I have ever seen that converters typically do not do anything with is on the frame and across the top between the drive and tag axles.

[Joe Cannarozzi]

What would be the down side of extending the connecting air line to the bus so the device could be mounted in a more assessable location, like the engine compartment?

[Jon Wehrenberg]

Converters all use the engine area differently. Virtually all the space accessible through the rear doors is occupied or required to access something, like the electrical box.

That leaves the RH side door above the batteries. Unfortunately that space is occupied in various ways also. Some coaches have house batteries above the chassis batteries and some have boxes designed to hold sewer hoses or other stuff like emergency reflectors.

I don't think AFO can approach every Prevost as a custom installation. They would go nuts trying to fabricate brackets and supports and other mounting devices depending on the type shell, the age of the shell or the converter.

So if the engine area is out, the next logical place is on the forward bulkhead in front of the drive axle. Unfortunately Prevost has used that space to mount the system for the hydraulic stabilizators on some coaches, and some converters like CC have used that open space to hold a condensing coil for their AC system making access to the bulkhead out of the question.

Behind the front bumper? Nope, some fill it with Cruise Airs, others have a drawer there, and some use it for things like the aux air compressor.

Steer compartment? Nope, some owner have hose reels or aux air compressors there.

In a bay? Nope, no two converters use bay space the same so there wouldn't be anything standard there.

That leaves between the tag and drive axles, and even that is going to be tough standardizing because of the accumulator tanks.

[0533]

The locations have the potential to vary because the buses vary. Prevost has evolved the buses to the point at which later models have accumulator tanks plumbed directly to the air bags. Those tanks occupy space that would be great for the braking system. So earlier models (early "T" and prior) would have plenty of room, but on later models it may be a challenge.

What Peter needs as a manufacturer is to see a variety of coaches and find the spot that is universal to all of them so he has a standard "Prevost" product. Once he has that place selected then the devlopment of attachments and connections and subsequent testing can take place. I strongly suspect that if the relay valve and tank are secured properly, and all connections to those devices have at least a short flexible section these problems now being encountered go away forever.

He cannot count on spaces in the engine compartment because converters use that space differently and the only area I have ever seen that converters typically do not do anything with is on the frame and across the top between the drive and tag axles.

Hello Jon,

I am about to repair the 3 lines that need to be addressed today. There are 3 lines to deal with, one that is almost cut off anyway that goes to the Toad from the front of the R-12 valve. On the backside of the valve is the supply line from the main bus air, then there is a line attached to a female connector that went to the AFO air tank which is now somewhere on 95.

You mentioned that "buses to the point at which later models have accumulator tanks plumbed directly to the air bags".

My question to you is: As part of my plan today is to raise the bus up on one side, place the Prevost jack under the raised side jack point and then crawl under and cut all 3 lines away from the R12 valve and the other small valve, seal them off so that I can travel.

Question: Is there any chance that by having raised the bus up on one side, and making these cuts that I might be affecting the air supply to the airbags???

I do not mind being stupid in these circumstances and would rather have a better understanding of what I am about to undertake.

Only 1 of the 3 lines seems to be live, the one that is coming into the backside of the R-12 valve which is not doing anything now as the air pressure is now at or below 80lbs as the bus compressor is no longer trying to supply air.

I am probably being overly cautious, but better safe than sorry. My wife is giving me a hard time about going under the bus.

[Jon Wehrenberg]

I think I understand the AFO system (I actually think it is a great system) and if my interpretation is correct there should be only one line under pressure. That line should be coming from the bus brake system pressure tank to the relay valve for the AFO system.

Unless and until you step on the brake pedal there should be no other lines pressurized. What is important for you to understand is that one line is likely a signal circuit coming from the brake treadle. That line must be securely capped or its origin plugged. The line from the bus brake system tank to the relay valve must also be capped or its origin plugged. Doing that will restore your bus to the way it was prior to the installation of the AFO device.

As to getting under your coach. If I were you I would raise the entire rear of the coach to its maximum. I would then put an unextended hydraulic jack under the rear support points behind the tag axle on both sides. For $60 you can go to a Northern, or Harbor Freight or any store that sells jacks and get a pair that are rated around 20 ton, and which have a center threaded adjustment. With the adjustment all the way out and the jack fully collapsed the weight of your bus will be fully and safely supported. To make sure the jack is adequately supported on the ground I would go to my local Lowe's and buy a 2 X 10, 8 feet long and get the guy there to cut it into 16" lengths (you end up with 6 pieces) and put them under the jacks to distribute the weight. That way even if the concrete is thin, or the ground is soft the weight is distributed and at an 1 1/2 thickness each you can adjust the jack threaded center to touch the body support point. Make certain the jack is under the correct body support point which is a 2 X 6 (guessing at the size) vertical tube member behind the tag axle and which likely has a heavy square tube running from the bottom of the one on the LH side to the RH side. If you have any doubts I will take pictures, but I think you will see the correct points

Your bus will be very safe to get under because once you raise it fully, and turn off the key the Norgrens will lock the air into the tag and drive axle air bags, and isolate them from the rest of the bus air system. Even if you purge all air from both brake systems and the aux system your air bags will remain inflated (unless you are experiencing the leans).

You can safely get under the coach because your air bags and tires are the primary support, and if you should somehow cut or break a line to the air bags the jacks will still support the coach.

The good news is that once you slide under the coach you can sit up and actually move quite freely in the area between the wheels.

Tell Pam you will be very safe if you do this, or let her read this post.

[Jon Wehrenberg]

Bruce,

I found this picture. This is the rear support point I am talking about.

I used two jacks in this picture because I did not have stands when it was taken.

[JIM KELLER]

Jon, Is this the same point we should use to support the Bus with the stands several of us purchased from you ? If so the small square tube would rest on the top of the stand. Correct ?