Quote Originally Posted by Jon Wehrenberg View Post
The system check valves are doing their job, and the broken fitting was located so the valves could work.

However, the lines to the relay valve appear intact, but one of them had been laying against the driveshaft and it was a question of time before it would have failed. When that line let go it became another air escape point. If the remaining line was then severed you have a third air escape point.

I am surmising the relay valve is not one originally installed on your coach, but is dedicated to the aux braking system. Even at that it should have been secured to the coach in the same manner as the original equipment valves are and the fact that it is hanging and is a few driveshaft rotations away from being ripped off tells me its mounting was inadequate.

Should you have an air loss that is in a location where the safety valves will not stop the leak your braking system air pressure will drop and once it falls to around 40 or 50 PSI your emergency brakes are going to automatically apply. It can be said the installation was a good one because you were protected from a catastophic air loss, but if my interpretation of the picture is correct and your relay valve was hanging as shown and the air lines were rubbing against a spinning driveshaft as it appears you could very well have experienced brake lockup.
I never experienced a loss of pressure while at highway speeds or even while at my first stopping location (red light). Not until I got to a the rv park and applied the parking brake did the pressure start to drop below 100lbs or so. It dropped to about 80lbs then the noise stopped. I then checked the bus for damage and found the hanging valve. I then released the parking brake and backed up the bus into its slip. The air pressure never rose above 80-lbs and the noise never returned. I assumed the tank suppling air to the valve had lost all of its air and now was locked out, but now I'm guessing if I were to have gotten back up to highway speeds the pressure would increase beyond 80lbs and the noise of escaping air would have started again.

My job now is to safely remove this line and seal off the fitting or the line itself to allow me to head back to Prevost for repair.

I must say it is very unsettling to rely on after market installs on these big buses and have such a poor result.

As a pilot, I should have been more involved in this install in the first place considering what was involved (air System), I was distracted by the POG events and was not there during the actual install process.

The funny thing here is that I got rid of my ridiculous Blue OX brake at the rally for this one and now am back to square one, plus now I am chasing my tail to figure out a way to get my Bus braking back to some degree of normalcy.