CDL School starts on Monday!

The explosion was more than likely caused by a loos or weak clamp on the chamber, then the spring sprung out with 120+ psi and caused the damage. That is what I would think, but I'm not a mechanic.

 

Loose/weak clamp on chamber? Not sure what you're referring to, but realize that no brake application was done at all when this happened.
Truck was easily cruising down the hwy at 70 mph. The initial damage was that the drum fractured and launched itself in pieces.
The brake chamber on that wheel was fine.

I have no idea what the actual cause of the drum failure was.
Maybe a previous driver, even months back, got it red hot and was cooled off quickly, becoming brittle (ie. iron tempering). Cast iron is known for that.
Maybe someone beat on the drum and caused a micro crack sometime back? I dunno.
Maybe a previous driver set the spring brakes and applied full pedal pressure on a hot drum, then when it cooled, it was metallurgically stressed.
Again, I don't know.

 

That was a few years back. I'll let you know when they're done! But refueling the reefer breaks the boredom!

I had to drop the trailer at that service shop and bobtail back to a terminal. I heard they had it fixed late the following day, as some parts had to be tracked down.
It also blew out that right hand air bag and took a chunk out of the lower bag mount.

 

Well... We went for a ride in one of the school trucks with an instructor... The instructor showed a classmate how to deflate and re-inflate the air bags, without getting out of the cab. We start off down the road with the airbag switch in the correct position and there is a brutal noise, it sounded like it was coming from the transmission. Anyway we pulled off the road and get out... Holy ####! The air bags are deflated! Turned the switch off/on (deflate/re-inflate) again they re-inflated... Switch failed the first time.