How to Prevent Brake Vibrations | Articles

[Editor’s Note: This article originally appeared in the June 2005 issue of Grassroots Motorsports.]

Story by James Walker Jr.

The year was 1962. The Beach Boys had just released “409,” an all-American, high school tribute to four-speed transmissions, dual quads and Posi-Traction. Their follow-up 1963 hit, “Little Deuce Coupe,” continued the band’s celebration of mechanical speed. And in 1964 the same group brought us “Fun, Fun, Fun,” clearly a lyrical homage to the Ford Thunderbird and the magical opposite-sex-attracting powers it possessed.

However, the title to their 1966 smash, “Good Vibrations,” clearly indicated that Brian Wilson was not a brake engineer.

Quite simply, brake vibrations are never a good thing. In fact, a common saying in the brake industry is this: “The best brake system is an invisible brake system.” Let’s try to understand why this can sometimes be so difficult to achieve.

Wouldn’t It Be Nice?

You press the brake pedal, and your car slows down. There’s no squealing, no shaking and no vibration. Please fasten your lap belts, close your tray tables, and return your seat backs to the upright and locked position—you have arrived at brake utopia.

Unfortunately, brake utopia can sometimes be in another ZIP code from you.

Pick your favorite brake system malady: brake roughness, pulsation, shudder, hot judder, shake, vibration, or the all-time favorite, rotor warping. To the brake engineer, these all have slightly different meanings, but to the average enthusiast they are all simply a pain in the—well, they’re a pain and we’ll leave it at that.

While usually not a detriment to brake system effectiveness at first, none of these conditions can be considered desirable. Few vehicle problems are as annoying as a pulsating brake system. And if they’re ignored long enough, these problems can have legitimate performance impacts.

So what causes these conditions, and what can be done to prevent them in the first place? We’ll get there, but first we have to go back to brake school for a quick refresher course.

Be True to Your School

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