Car Care: Braking the sound barrier

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Brake pads can vary based on the quality and brand of the product used. Photo / Supplied

Brake pads can vary based on the quality and brand of the product used. Photo / Supplied

Most of us can relate to this scenario. You are slowing at an intersection but, instead of coming to a stop quietly, your brakes squeal and scream their way to a halt.

It could be a sign that your brakes require some attention. With so many parts to a braking system, there are a few common issues that can be experienced during the ownership of a vehicle.

Vehicle braking systems rely on friction generated between two components of different material types in various combinations of a steel disc/brake pad, or steel drum/brake shoe as a method to slow a vehicle. There is a high possibility for a brake system to make noise.

Brake pad material construction can vary based on the quality and brand of the product used. Pads can have high heat and noise resisting capabilities, and low wear or dust generating capabilities. However, sometimes the better the brake pad, the harder they are on the disc they run against.

The downside of replacing pads only
If an old disc just gets new pads, they will need bedding in and there’s a high chance that the brakes may take longer to be as effective as they once were, and noises may also develop.

This is because the new pads have a smooth flat surface, while the old disc may have scores and scratches from the old brake pads.

To prevent this happening, a portable lathe can take a small shaving from each side of the disc, giving it a nice smooth surface like new.

A downside to this is that the disc gets thinner every time a disc is skimmed which can make it easier for a brake disc to warp in the future.

Ultimately if the discs are getting close to their limits, it would be best to put new discs on with a fresh set of pads.

As most of the braking force is carried out by the front disc brakes, the rear brakes (discs or drum) are unlikely to need attention as often. A rear drum brake system incorporates the same principles as disc, but the construction and operation methods slightly differ.

Brake fluid is the life blood of the braking system; it is also hydroscopic (absorbs moisture from the atmosphere). It provides the link from the brake pedal to the components doing the work at the wheels. Every vehicle has a recommended brake fluid replacement schedule that ensures the fluid remains clean, fresh and free from moisture.

When’s the right time to replace?
Brake pads have warning indicators to help inform drivers when they should be replaced. Metal strips are set to a specific distance where they’ll start to rub against the disc when the pads become just a few millimetres thick, alerting the driver that the brake material may be low.

The indicator rubbing noise is usually most noticeable when the brakes aren’t applied and it’ll become less obvious when the brakes are used. If you notice this happening, it’s best practice to go to a garage to get the pads replaced.

If you are driving a vehicle with noisy brakes, get them checked as soon as possible. It could be something simple or there may be signs that more work is required. Either way, it’s important to take a closer look to ensure your vehicle stays safe on the road.

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