We at Leith Porsche make it our mission to connect people with their perfect car. We believe that the more you know about cars, the more you’ll love them, and that’s why we’re here to tell you all about brakes.
We step on our brakes every time we get into our car (hopefully) and people seem to be very well acquainted with their use – especially in free flow lanes. However, few know much about the actual hardware behind the braking process.
Rather than cover what we hope is the obvious importance of brakes, we’re going to outline the two most common types of brakes. We’ll examine their strengths and weaknesses in everyday use, show you how they work, and then compare the two.
Drum Brakes
Drum brakes are the original in-tire braking system. Before their introduction, brakes were essentially a block of wood on a lever that pressed against the tire (also known as a handbrake). The first drum brakes were released in the year 1900 on a Maybach, and were patented two years later by legendary automotive engineer, Louis Renault.
We could write a long explanation of how drum brakes work, but you can’t beat an informative video:
Problems with Drum Brakes
Since the components of a drum brake are all housed within a metal drum, they tend to heat up very quickly. When drum brakes heat up, they fail because hot brakes produce less friction. The less friction they produce, the less effective they are at slowing the wheels. This is often referred to as brake fade.
While modern drum brakes have come a long way in terms of design, brake fade is still a major drawback to their use. For this reason, drum brakes are typically found on either the back wheels of a car, or nowhere at all. Their replacement? Disc brakes.
Disc Brakes
Disc brakes were patented by Frederick William Lanchester in 1902, the same year Louis Renault patented drum brakes. Although they were the superior design, it would take half a century before the technology could successful manufacture the necessary parts.
In 1953, Jaguar – a small company at the time – developed the first reliable caliper disc brakes for their C-Type racing car. They entered the C-Type into the 1953 24 Hours of Le Mans, and took home first place. Later that year, Austin-Healey’s 100S would be the first production car sold with all disc brakes.
Since that time, disc brakes have become the standard for performance vehicles. They function upon the same friction principle as drum brakes, but are less prone to failure from overheating and dry quicker when wet. This is because of their open-air design, as opposed to being housed in a metal enclosure, like drum brakes.
Again, here’s a fancy video detailing how disc brakes work:
Drum vs Disc
So which brake type is better? As with most things in life, the answer is rarely clear-cut. Drum brakes have some major design flaws: they overheat too quickly, take longer to dry off, and are typically heavier than disc brakes.
At the same time, disc brakes cannot be used as a parking brake because they expand when hot and contract when cold. If we relied on them for a parking brake after using them, they would eventually cool off, shrink, and lose contact with the brake disc. Obviously we’d have a problem here.
The two brakes are just different. Disc brakes are the more effective and reliable choice, but they have their limitations. Drum brakes are not very practical, but they are crucial to parking a car – unless of course you’d like to go back to wooden blocks on sticks.
Therefore, drum brakes are often still found in modern cars. Manufacturers will usually outfit the front wheels with disc brakes since they have to work the hardest, and drum brakes in the rear. Some sports cars will use disc brakes on all four wheels, but have one additional drum brake for parking purposes.
Speaking of Brakes
Could you use a new set? It might be time if you’re starting to hear some squeals when you brake. Feel free to come by the Leith Porsche service center and we’ll take a look for you. Sometimes that brake-noise could just be debris on your brake pads, but it can also indicate they need replacing.
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