CDL Test question on brakes

My incident (listed in Post #19) happened in darkness, around midnight, doing 70.
25(2)+2's major 'what the heck just happened back there' moment sounds exactly how I reacted, except for me was more like "what the heck just happened".
I heard an explosion-like sound (couldn't tell where from), which was instantly followed by what felt like a sideways load shift, while in a microburst heavy cross wind.

Truck instantly began loosing speed & acted like someone turned the ignition key off. I had control, and was pressing hard on the fuel pedal (as one should do in a blowout situ), but had no idea at that point if I lost a tire, lost my rear tandems, or even if a Prius was wedged/stuck under my trailer. No idea what the heck was wrong.

Wasn't until I came to a stop on the shoulder, grabbed my triangles, and on the way back to place them, saw the carnage at the RF tandem.
Point is,, I had no idea what caused the drum to "let loose". I had figured it was due to a previous intense overheating of the drum followed by too quick a cooling(water), by some previous driver leaving it brittle/partially cracked (was 1st time I had ever pulled that trailer). But now see how heyns57's info (Post #8) could have been the "culprit". Possible.

 

There may have been a defect in the metal that finally reached critical point and it let go. Sometimes we'll never know and all we can do is think how grateful we are that no one was hurt when it let go. I haven't had the pleasure of having a drum explode (and hopefully never will). Worst thing I had happen was losing a steer at highway speed. I think the 4 wheeler I was passing pretty much needed new shorts after that happened (big cloud of smoke, big bang) but the tread stayed with the wheel and I was able to pull over and wait for the tire company to replace.

 

Whew.. Glad you made it thru that steer tire blowout, without getting hurt or worse, Skan.
That's always one of a driver's most UNdesired "things that can go bad".

While I'm here I wanted at add an important (unwritten) part of my prior post, for new drivers, or anyone for that matter.
After seeing that my entire brake drum was literally "gone", my first concern was "Where the he** are the pieces? and How big are the pieces?".

I feared that possibly a large size piece (1/3, 1/2 drum?) could likely be on the highway, up to a mile back, or so.
One of my first actions was calling State Police, alerting them to that possibility, so that they may send a road crew to check for a surely dangerous safety hazard to any other vehicle approaching that section of highway. They quickly got a road crew driver out there, who scanned the last mile or two, driving on the shoulder with a spotlight.

Luckily, no chunks were found on the traffic lanes.
My point is, aside from handling your own damage & mishap, also be thinking of others.
And take the proper steps in order to prevent a one vehicle incident turning into a far more serious incident to another innocent motorist.

 

I was lucky, that was for certain. All the tire stayed with the truck, the rim wasn't damaged, and just a little black marking on the chrome bumper. All in all a lucky outcome. Things easily could have gone seriously wrong if moving to the shoulder and it was soft or gravel and not asphalt, but all in all, remaining calm and small movements kept the situation from getting out of control. That is truly the hard part and you cannot teach it. Experience comes with time but groups like this can help, but no substitute for being out on the road.

Happy trails.

 

I'll add to that very hot brakes could mean he smoked them. That happens when the shoe linings actually liquefy and glaze over. Setting the parking brakes immediately could fuse them to the drums just like frozen wet brakes.

For the newbs if you aren't on fire continue driving without braking and let the wind cool them down. It's not a wood fire, it's metal and shoes. Pulling over in a panic not only adds to the heat from additional braking, it lets the heat radiate out to the tires which is where the fire starts. I forget the name for it but when a tire gets so hot a chemical reaction starts and there is no stopping it. Throw you a tire on a wood pile and if you don't get ticketed for illegal burning you'll see what a burning tire can do.

 

Parking breaks are for parking. Your answer is correct a steep hill or if brakes are hot is not a proper time for the parking break

 

Lol nope the incident with my shoes freezing happened in Nebraska. Hell I thought they were going to freeze Monday night in south dakota luckily they didn't. But I had to set BOTH trailer and tractor on the road outside of the barn in faith to keep my truck from sliding. It was slicker than sheets at a 5 star Monday night. But yep yep I've had my shoes freeze before its a PITA!!! Blow torches help out as well....don't ask me how I know lmfao.

 

posted here by mistake