Alert !!!!/ Toad Air Brake Tn rally

[0533]

Thanks Jon,

I will find the necessary jacks and lumber and go to work.

Brent at AFO wanted me to go to NAPA and get a couple of qtr. inch nylon female air fittings to make a temporary seal on the offending airlines.

I went to NAPA and they did not have anything that would work on the black air lines.

I am going to crimp and secure the lines with 3 wire ties on each crimped line, super gluing the open ends and wrap all in tape. I think this will provide a temporary fix that will allow me to drive the 160 miles or so to get a real repair.

[0533]

Great shot, this helps me better understand what is needed.

[Orren Zook]

Bruce,

while you're under the coach could you take a couple photos of how this device is plumbed up - I'm having a little trouble picturing it. Thanks in advance.

[phorner]

Good luck, Bruce.

If you happen to have any "Rescue Tape", it will hold against considerably high pressure and can be used after you crimp the offending air line(s) in addition to, or instead of, the wire ties.

Take plenty of time to secure the jacks and assure yourself that the bus is supported. We took the better part of an hour to study/jack/support the bus before anyone crawled underneath.... to make a fix that only took a couple of minutes.

Be safe and we're all hoping for a good, and final, solution

[0533]

Bruce,

while you're under the coach could you take a couple photos of how this device is plumbed up - I'm having a little trouble picturing it. Thanks in advance.

I will be happy to take some pics, but unfortunately much of the install is either dangling from its air lines or has completely left the bus for a better place somewhere along I-95, but I plan on taking some and will share them with everyone.

[Jon Wehrenberg]

Bruce, It would be easier to follow the AFO installed lines to their origin, remove them and just use a 3/8" or 1/2" plug.

Orren, If I am wrong I assume Peter from AFO will jump in and slap me, but the relay valve is getting a signal from the brake treadle, and the relay valve is taking air from the brake system air tank and is passing it through the relay valve (modulated by brake treadle signal pressure) to the toad braking device under the hood of the toad.

I don't know if the tank is the supply to the relay valve or is downstream from it (I suspect it is the toad relay valve supply).

That air pressure to the toad, modulated by the relay valve is used to maintain vaccum on the toad brake vacuum booster via pressure venturi installed on the toad, and to actuate a pneumatic cylinder to actuate the brake pedal.

I'm pretty sure, but if wrong this needs to be corrected.

[Orren Zook]

My problem visualizing this is - how does the second relay valve, I'm assuming installed by AFO, get it's signal to operate. Is another service line installed from the foot valve to this relay valve? Does the R12 receive it's air supply from one of the main system tanks? If not, where does the air supply come from? And what is the purpose of the small air tank shown in the earlier picture? Does it supply the cylinder in the toad that operates the brake? I took a brief look at their web page but didn't see any schematics.

[Jon Wehrenberg]

Hopefully Peter will chime in and post the correct answer. I suspect the signal from the foot treadle is picked up somewhere, perhaps a "T" off the line at the Prevost relay valve.

I suspect the tank is installed to serve the toad, and it picks up a protected line from the Prevost installed braking system tank. I am sure that line protection is what kept Bruce from dumping all his air. I suspect that might also tee off a line perhaps at or going to the Prevost relay valve.

At least that is what appears to be a logical approach. I seriously doubt if they would run a parallel line from the treadle, so they created a miniature version of the bus braking system picking up the air signal and tank pressure (to their relay valve) at convenient spots in the rear.

[0533]

Good luck, Bruce.

If you happen to have any "Rescue Tape", it will hold against considerably high pressure and can be used after you crimp the offending air line(s) in addition to, or instead of, the wire ties.

Take plenty of time to secure the jacks and assure yourself that the bus is supported. We took the better part of an hour to study/jack/support the bus before anyone crawled underneath.... to make a fix that only took a couple of minutes.

Be safe and we're all hoping for a good, and final, solution

Hello Paul,

I have never heard of "Rescue Tape", what is it and where can I find it??

I plan on taking my time with the jacks and will be sending my wife's mother under the bus to take pictures before I start my project.

[phorner]

Bruce, I have posted a link to Rescue Tape. It can be found at most truck stops and hardware stores.

Really good stuff!

http://www.rescuetape.com/


However, Jon's recommendation to follow the lines to their origin and use a plug is the best solution. You just need to have the correct plugs/caps when you start. I wouldn't make a second trip under the bus if I didn't have to, so if you don't have the parts, I wouldn't make a trip under just to take notes and measurements and then search for the correct fittings.