Even P buses have bad days!

[mbulriss]

(04-16-2015 20:53)davidbrady Wrote:  There's more over here. My speculation is that it was a dragging brake caliper that caused the heat that caused the blow out that fueled the fire. The older style Prevost disc brake has a rubber boot covered sliding pin caliper design. The rubber booties disintegrate exposing the pin to the elements. Rust and corrosion sets in preventing the brake caliper from releasing. The solution is to keep the pins lubricated and the booties in good shape, or upgrade to the latest calipers.

I'd say it pays to get out once in a while and shoot your wheel assemblies with an IR thermometer.

These comments above about excessive hub heat coincide with my first casual thoughts about the blow out and subsequent fire. However, at the Lone Star Birds rally over the weekend, one of the members that recently purchased a P bus H3-45 pointed out another possibility. He noted that right over the tag axle on the passenger side, there is a battery bank. His suggestion was that a normal road hazard (or old age) blow out could have flung a steel belt around in there, ripping and shorting some battery cables, thereby causing some serious arcing and a resulting fire. It's certainly another plausible theory. It also gives me pause to remember that the house battery bank on most wide bodies is very close behind the tag axle tire on the passenger side also, close enough to generate lots of heat evaporation on the leading batteries in the trays (at least that is the seeming affect on my bus). Because of that, I have recently insulated the area in front of the battery slides to try and cut down on the heat transfer. As a result of this discussion, I think I may have to take another closer look at how to further protect the cables that hang on the back side of the battery bank.

BTW, I do agree with the IR thermometer suggestion and carry one to randomly check hub and tire temps on long runs. Just replaced the battery in it last weekend.

FWIW,