"We think the brakes failed."

Brakes don't 'go out'. They either weren't set or were seriously out of adjustment

 

He probably only had spring brakes on one drive axle...which is fairly common. It isn't unheard of for a loaded truck to roll down a hill with only the tractor brakes set in that case, and it happened to a guy I used to work with (causing a change in policy at the kiln where it occurred which increased loading times since we were no longer allowed to pull off the scale out from under the silo to go inside and get out paperwork while the next truck pulled in to get loaded. The springs get weak with time, and don't quite hold as well, leading to a roll-off like that if loaded heavy and parked on a hill. Simple solution is to pop BOTH the yellow AND the red valve when parking on a hill, because the trailer will typically have spring brakes on both axles. Instead of having 1 axle trying to hold the load, you'll have 3. If the driver only set the spring brakes on the tractor, it is partially his fault with the equipment bearing some of the blame. He may have been parking the truck in that manner for YEARS before the springs were worn out enough to not hold that one time...expensive lesson to learn.

The other possibility is that he parked it using the hand valve without setting any spring brakes at all. If the valve released on it's own, or if air pressure leaked off while the truck was parked, it'll roll away. If THIS is what happened, the driver will probably be out of a job because it is 100% driver error. The hand valve IS NOT a parking brake.

 

Classic excuse. Brakes went out, pffft. ( like bent bumpers that are caused by the "mystery deer")

 

Or the truck was a POS and all the park chamber springs were broken.

 

If there was a problem with the spring brakes, a proper pre trip would of discovered that. No matter how you slice it, this one is all on the driver.

 

"The company was able to remove the truck quickly and return it to Volunteer Equipment’s parking lot."

Yeah, I bet they were.....

 

darned Macks......

 

Sad. Once in our town a semi-truck had parked up the hill from a convenience store, about 1200 feet or so. It rolled off of the hill and into the west side of the convenience store. He had left it our of gear and did not put on the park brakes, he had not been driving very long. Thankfully no one was injured

 

Some years ago, I drove a 26' box truck w/ab, delivering appliances for Sears. I had been assigned to training a new helper for the day. This particular day was chilly so I decided to keep the truck idling at stops. Fourth stop has a moderately steep downgrade drive, it's a bit long no big deal, back down drive set brakes, throw it into neutral proceed with delivery. My permanent helper and I were finishing up installing appliance, we send the new guy out to close the doors on the truck and wait. I was gathering signatures, and helper cleaning up. Suddenly the has is shaking hard with a loud kaboom, being a vet my first thought was claymore. Gathering our wits, we find a big white box truck in the middle of the rec room and a very white black man in the passenger seat. Turns out he was curious about the big button on the dash and decided to see what it was.