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Truckers are invaluable by helping deliver goods and connecting businesses. Keeping their rigs in good shape is an essential part of their job. This can mean keeping the engine running when necessary or preventing brake lines from freezing up. Truckers have used unusual items to get their truck going, like alcohol in the braking system. Why did they do that, and was it beneficial?

How air brake systems work

Trucks driving on the road driven by truckers, which used to pour alcohol in brake systems.
Trucks driving on a highway | Anderson Coelho via Getty Images

In a standard car, brake pressure gets transferred to other components through the brake fluid. If you lose brake pressure, you could lose your brakes. For an air braking system, there is no brake fluid. It uses air in the lines instead.

According to The Autopian, you’ll see several parts for this kind of brake. First, the air compressor supplies the pressurized air to the system and runs while the engine runs. Then there’s a storage reservoir where compressed air is kept until needed. 

Another part of the system is the brake pedal. When a truck needs to stop, the driver presses the brake pedal to initiate the process. Air is transferred from the reservoir to the brake chambers, which start the braking operation at the wheel. 

The key to successful braking is having pressurized air stored in the reservoirs. Before beginning any journey, drivers need to check the pressure gauge for the air. 

If pressure is too low, it will engage the “park brake” to keep the truck from moving. When enough air has been pressurized, the driver can release the brake using the hand control to move the truck. 

These big trucks don’t use regular hydraulic brakes like cars because they need something that will stop a large vehicle like the semi. A car’s drum brakes wouldn’t be able to stop it.

Why pour alcohol into the brake system?

Cold weather is a truck driver’s nemesis for keeping the fuel tanks warm and preventing freezing brake lines. Moisture in the system could condense, and what happens when moisture meets frigid air? It freezes. 

Semi-trucks often have icicles forming on the brake lines when temperatures drop low in winter. Frozen moisture on the inside of the braking system will cause jams, which can lead to locked wheels, and when that happens, the brakes don’t properly work. The last thing you want is a large semi having no ability to stop. 

Alcohol is the solution to that problem. This kind of alcohol doesn’t freeze at zero degrees like water does. Temperatures have to drop below -50 degrees before they succumb to the cold. This way, the driver doesn’t have to worry about not having the brakes when needed. 

Did the alcohol benefit truckers?

Alcohol in the system was mainly used years ago, but a few truck drivers will resort to it today in a pinch. Since technology has advanced, there have been other products on the market to help with freezing air brake lines, including air dryers and alcohol evaporators. 

Air dryers remove moisture and other debris from the air before it gets pumped into the reservoir tanks. An alcohol evaporator injects the methyl alcohol into the air stream to mix it in so that it adheres to any remaining moisture that may still be in the air. It is then passed on into the storage tank. 

The problem with pouring alcohol into the air brake line is that it can cause an explosion. The Autopian article explains that one gentleman had taken a torch to the underside of the truck trying to unlock his tires that had frozen brake lines. He didn’t know the air tanks had alcohol in them, so they exploded, blew a hole in the trailer floor, and bent some of the bracing. Luckily he wasn’t seriously harmed.  

With larger vehicles, there’s more weight that needs to stop, so manufacturers install an air brake system on semis so it can handle slowing down the large truck. In the past, drivers used alcohol in the brake system to avoid freezing the lines in cold weather, but nowadays, other products are designed to prevent locking up the wheels so the truck can still stop when needed.


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