Smoking Brakes

I was driving through West Virginia and Maryland along I-68 with a full load (44k of paper). It was not a real mountain road, but still had many hills. I was going up on most of them at 35-30 mph with flashers. When doing down, I gained speed up to the limit. The engine brake setting (it is a Volvo) was set at maximum. I tried to brake as short and fast as could, and yet at some point I saw some smoke from my tandems. I stopped immediately, tiers were OK, but all four shoes were smoking, and I mean a whole lot of white smoke. My question is what should I have done to prevent it? I saw a couple of trucks with the same problem, either passing me or waiting on the shoulder, but the majority had no smoke at all, including some heavy loaded as well.

Short answer, slow down. I used to run 68 back and forth to Maryland quite a bit between 145-150,000 # and never overheated the brakes. Pick the proper gear, set the engine brake and let the truck do all the work.

Yep, like Robert said. Set it to manual, lock it in a lower gear and only use the service break if you absolutely have to.

Yep, like Robert said. Set it to manual, lock it in a lower gear and only use the service break if you absolutely have to.

I saw an M setting, but never tried it. Is it OK to switch while driving or I need to be stopped?

You can do it while driving. It'll just lock it in whatever great it's in. There should also be a switch somewhere that allows you to upshift and downshift. Try it out one day on the highway. If you're nervous, do it when the highway is empty and you'll see what it does.

Thank you, I appreciate the advice.

Andrey, you can switch it while driving. When you are in the M mode you will use the two buttons on the left side of your shifter to change gears. The top button will up-shift and the bottom one down-shifts. To keep your brakes cool you just have to drive in a way that allows the truck to do the work. The engine brake and transmission can do a lot more efficient job of controlling the truck without producing all that friction that the brakes do. That friction is of course the source of the heat.

One of the major causes of brakes overheating is brakes being misadjusted. Your tractor will have self adjusting brakes, but most trailers do not. If you hear humming or squealing from your trailer while braking, that is usually a tell tale that they are off, but not necessarily out of spec. With properly adjusted brakes, using the engine brakes and proper service braking habits, you should not be overheating your brakes. Volvos have pretty good engine brakes. It seems you have an automatic 12 speed. check if your transmission interface lets you downshift manually. you should be going down a hill in a gear low enough to get your engine to 1500-2000 rpm for proper engine brake performance. The volvos let you bump the engine brake stalk all the way down past '3' to maximum engine braking mode. I would use that only if you get in a bind as the only way to cancel that is to switch to '2' or tap the accelerator and this may cause the trans to upshift or otherwise throw you off. Usually when you go to setting '2' it will downshift and may drop another gear when switching to '3'. Definitely read your owners manual as those trucks are sophisticated.