The Inside Story Of Drum Brakes

Drum brakes are seldom found on today’s cars, yet are still fitted to trucks and farm machinery due to their effectiveness and affordability. Jake Venter takes a closer look at this design.

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Most modern cars are fitted with disc brakes front and rear. This layout is easier to service, less prone to overheating, and provides a linear response to the driver’s pressure on the brake pedal. In contrast, drum brakes become less effective the harder you push on the pedal. Despite this, most trucks and bakkies, and even some cars, are still fitted with drum brakes at the rear. Some heavy vehicles also have them at the front. The reasons drum brakes remain popular is that they work very well at reasonable speeds and are cheaper to manufacture.

Many tractors, trailers, caravans and other wheeled farm machines are fitted with drum brakes, and their servicing can usually be undertaken quite easily on the farm. Drum brake shoes can be activated in one of five ways, depending on how the pivot points and wheel cylinders have been arranged. This not only has a bearing on the way the brakes perform but also affects the rate of wear and the amount of confusion you will experience when you decide to remove the brake drums for a service.

• The simplex brake