What Causes Warped Brake Pads – And How To Fix Them
Have you ever experienced the somewhat frightening experience of applying pressure to your brakes, and having your steering wheel shake violently – or perhaps even cause the car to veer slightly?
You may have warped brake discs; there are numerous reasons for the cause of warped brake discs, some of which are easily remedied.
We outline the causes behind warped brake discs, as well as how you can go about having them repaired – and prevent the same thing from happening again.
Warped Brake Pads: What causes them?
It’s important to understand that warped brake disc (also known as a rotor) is not simply a disc which is misaligned; a warped brake disc refers to the flat surface of the disc becoming uneven.
Heat is the number one cause of this, and can cause warping in more than one way:
Glazing the brake rotor with material from the brake pad. This happens because brake pads, similar to tyres, are made with different amounts of hardness and stickiness depending on the intended purpose. When brake pads made for normal road use get very hot from high-speed driving and braking, or from riding on the brakes for a prolonged period of time, the material can get too soft and basically “paint” the brake rotors. This means that the brake pads won’t grip onto metal when the brakes are applied again, causing decreased brake performance that is less smooth than before.
Wearing down the surface of the rotor and making harder spots in the metal stay slightly raised off the surface. The reason for this is quite simply the metal of the rotor is harder than the brake pad applying friction to it, the pad wears down while the rotor remains largely unaffected. With excessive heat, the metal becomes soft enough for the pad to wear down the rotor surface. This means that slightly less dense spots in the metal wear down faster and make the harder spots stick out, causing warping.
Another common reason is the rapid cooling of a highly heated brake pad; driving a long distance or having applied your brakes heavily will cause a surge in heat. If you were to drive through a puddle of water in the road, your brakes are instantly cooled – without allowing the metal to cool naturally and return to its regular shape. This rapid cooling causes the brake disc to warp.
How Do I Know if My Brake Discs Are Warped?
You may hear excessive squeaking when the brakes are applied or even smell burning rubber.
Braking suddenly becomes jittery and inconsistent.
The vehicle vibrates when coming to a stop.
How Do I Prevent My Brake Discs from Warping?
Be mindful of how much braking the vehicle is doing compared to what is done during normal operation. When driving down-hill, try to control the speed of the vehicle by shifting the gears into a lower gear, instead of applying the brake by “riding on it”.
When brake pads are first installed they should be properly “broken in” or “bled”, to ensure they don’t leave too much material on the brake rotor. This is usually one by the mechanic fitting your brakes.
Avoiding harsh braking when the brake rotors have gotten hot from prolonged use will also go a long way to ensuring your brakes do not become warped.
h/t to yourmechanic.com for sharing the information sourced in this article!
Related Tags: Brake Booster Repair
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