Alert !!!!/ Toad Air Brake Tn rally

[0533]

Your picture shows a standard Bendix R-12 relay valve (with 4 port) and a pressure regulator (it doesn't permit air to pass through until a preset pressure is reached, usually 65 or 95 pounds) dangling by nylon tubing. I'm sure the howling you heard was your rear brakes engaging as the parking brakes began to set up. No low air buzzer? Just lights and a gauge? Why wouldn't the manufacturer just tee off your existing relay emergency valve? Was that R-12 added by your toad brake supplier? I carry an assortment of tubing fittings in various sizes so I can cap a line if necesary so I can get off the highway and to a service provider.

Hello Orren,

I am not nearly a well versed about this as I should be, but could I ask a few questions.

1. The Howling sound while driving off the ramp seemed to be escaping air from under the drive axle. The pressure on both dash gauges were reading 120 lbs, and no low air pressure lights or alarms were on.

When I arrived at the RV park where I leave the bus and was setting still the howling sound continued, but the air pressure began to drop until it reached 80lbs, then the howling noise stopped.

I inspected the bus carefully and did not notice any damage or heating around the brakes of the bus or the toad. I am very concerned by your and Jon's comments about the drive and tag service brakes being on while driving along at highway speeds. When my brakes are applied I see a light on the dash that shows that the brakes are on, is this light attached to the pedal and not the actual brake, and if so then why did I not see red hot brakes or even some smoke or something. I am getting increasingly more upset about this whole dam experience.

I do know that the Air Force One install taps air from the main or secondary tank, but know that it runs to the R-12 Relay you mentioned, then to a small air tank installed by AFO) then to the toad.

I think that somehow the drive train catches the line or hits the R-12 relay and severs the fitting from the R-12 to the AFO tank and the end result is that it falls onto the spinning drive shaft (PS> scrapping up against it leaving lines scraping around it, hope this does not damage this shaft).

I was under the impression from AFO that in this event there would no effect on the main braking system, but it does not appear to be so as it must be placing a stress on the entire system trying to keep the air pressure up for braking. I also wonder how effective the brakes would be in an emergency braking situation??

Finally I am not a big fan of going under the bus to fix for the second time an install that should not require any service and repair.

My plan is to raise the bus on one side, place the Prevost hydraulic jack under the jack point on the high side, go under and cut the line from the R-12 to the Prevost air tank, crimp and secure the cut line, seal it somehow and then have the entire thing removed and start over, including careful inspection of the drive shaft.

When this happened before I had Prevost Jacksonville reinstall the unit make a new fitting for the R-12 unit and place the whole thing out of the way of the drive shaft so this would not happen again. I do not feel that AFO has completely engineered this install for our buses to insure against this happening?