by Nick - Driven Forensics
•
16 February 2025
This post forms part of a series of forensic vehicle examiner posts, where we answer as many of the commonly asked questions we get as a forensic vehicle examiner. Our aim is to answer the most commonly asked questions and to dispel certain myths that lurk. If you have a question for our forensic vehicle examiner, simply drop us an email at enquiry@drivenforeniscs.co.uk The brakes on your car are incredibly well designed and complete brake failure is rare. The cause of any brake failure should be investigated, either by your mechanic or vehicle technician, or if you are involved in a serious collision, by a forensic vehicle examiner. But what are some of the most common reasons brakes fail? Brake pad or brake lining failure Brake pads or brake drum linings, are specifically designed with a friction material to withstand the heat generated when braking. The friction material is mounted to a backing plate, and when braking, that friction material is forced against the brake disc or brake drum, which causes the vehicle to slow. As the friction material reduces or is non-existent, the ability to disapate the heat created during braking is reduced. Where the heat continues to build, it can lead to brake fade. Brake discs or brake drum failure Brake discs or brake drums are a key component in the braking system. The discs and drums are essential in disapating heat as well as giving the pads/linings a surface to grip to. Where the discs become too thin, are contaminated with something (i.e. oil etc), pitted or seriously worn, this can lead to reduced effectiveness and can, in exterme circumstances, lead to brake failure. Low brake fluid levels or brake fluid leak In order to apply the brakes, fluid needs to be forced through the brake lines to each wheel. Where the brake fluid is either low or there is a leak in the system, the fluid does not reach the brakes and therefore the brakes cannot be applied. It is worth saying that the brake fluid system is a closed system, meaning the brakes do not consume to fluid, so there should be no need to top it up. When your brake fluid is low, it can either be a sign that your brakes need replacing or you have a leak. In either case, it is worth taking your car to your local mechanic or vehicle technician to have them checked. Seized brake caliper / seized wheel cylinder When your brake calipers or wheel cylinders seize, they can seize in either the on or off position. When they seize in the on position, the brakes on the wheel will be permanently applied to some degree, meaning heat will quickly build up and likely lead to brake fade and brake failure. When they seize in the off position, no matter how hard you press the brake pedal, the brakes simply will not apply, meaning you have no means of slowing your vehicle down using the brakes. Driven Forensics in-house forensic vehicle examiner can assist you in determining whether a vehicle has suffered a brake failure, and if so, why. During a forensic vehicle inspection, not only do we inspect each component, but we also photograph and document their condition for later use in Court and other proceedings. If you need a forensic vehicle examiner to inspect your cars brake system during a forensic vehicle inspection, contact us today. T. 0113 534 8708 | E. enquiry@drivenforensics.co.uk