Haynes shows you how to make sure your brake pads are in good condition

Brake pads wear out. There's simply no avoiding it, mainly because they're designed to wear with use. In doing so, they save much more expensive parts from needing to be replaced. But you need to keep an eye on them, because while wear won't cause a catastrophic failure, it can increase stopping times.

What could have been a close call, may now result in a fender bender instead.

Ideally you’ll want to replace your brake pads before they get to this point where the metal baking plate contacts the brake rotor, because it can quickly wear grooves in it. That’s why it is important to check the thickness of your brake pads at every tire rotation, or at least once a year.

Why Do Brake Pads Need To Be Checked?

They may only be small, but the brake pads play a vital role! The braking system consists of hydraulically actuated pistons, within the brake calipers. The pistons force the brake pads against the brake discs and use friction to convert kinetic energy (motion) into thermal energy (heat) – which is why brakes get hot in use.

The actual pad consists of a steel backing plate covered with a layer of high friction material. As you brake, minute amounts of this material are worn away by rubbing the disc, and create the dust which coats your wheels.

The composition of the friction material is what dictates how well the pads grip or bite, and how quickly they wear. Different compounds of pad may last longer, but not bite as hard, or resist brake fade caused by heat.

There is always a trade off between performance and service life, and some pads are designed to keep working in extremes of heat that would otherwise damage a 'normal' brake pad.

As the pads wear down they need to be replaced well before the steel backing makes contact with the disc. Some pads require a visual inspection, some incorporate audible wear indicators (that squeal as the brakes wear low), and others contain sensors that trigger a warning light on the dashboard when they get to a prescribed limit

Discover how to replace the front brake pads on your car!