Brake System Guide

How does a brake system work?

Typically brake systems include a few simple moving parts that (when working properly), quickly slow and stop your vehicle. When you step on the brake pedal, a vacuum booster (also known as the brake booster) is actuated.  This multiplies the amount of force applied by your foot when stepping on the pedal. Without the added force produced by the brake booster, stepping on the brake pedal would require a large amount of effort.

The force is transferred to the master cylinder, which is a reservoir filled with brake fluid. The master cylinder (typically controls two sets of brakes) uses the brake lines filled with brake fluid to actuate the brakes on the rotors. The master cylinder applies even pressure to the front and rear brakes when you step on the brake pedal. The advantage to having two systems is that if one were to fail, the vehicle can still be stopped.

When you step on the brake pedal, you are controlling the brakes with the hydraulic action of the fluid in the brake lines. This means that every time you step the brake pedal it moves hydraulic brake fluid to actuate each individual brake.

Disc brake components

A disc brake system involves only a few parts to create a stopping motion. When a wheel is removed from your vehicle, the first thing you may notice is likely the rotor. This is the “disc” in the disc brake assembly. The rotor is attached to the wheel hub directly.  This means that when the wheel spins, the rotor spins as well.

The next most significant component of the disc brake system is the caliper.  This part fits securely over the brake rotor (almost like a clamp). Within the caliper are the brake pads. The pads are the part of the brake most responsible for slowing and stopping. The pads are pushed into motion by the brake piston (also within the caliper). These two metal or ceramic plates come in contact with the rotor which uses the power of friction to slow the vehicle.

Since the vehicle’s stopping power depends on two surfaces coming in direct contact, both the rotor and the brake pad need to be clean, level and free of debris. While brake pads are designed to be durable, they wear down over time.

Signs of Failing brakes

Brakes are considered one of your vehicle’s most important safety features.  If your vehicle has signs of failing or faulty brakes, they should be serviced immediately.

Although brake assembly components such as brake pads and rotors are designed for durability due to their frequent use, brake components do eventually wear down and need to be replaced. There are some clear, and not so obvious, signs that indicate brake repairs are needed.

Grinding

When brakes grind, it not only makes you cringe, but it’s a clear sign that your vehicle’s braking system requires service. If you witness grinding noises when you step on your brake pedal, it means the pads are overdue for replacement or that something is making contact with the brake rotor the wrong way.

If grinding is occurring, the brake pads are likely to be beyond their wear limit, they may be coming into uneven contact with the rotors, or it could be something more serious such as the brake caliper or piston grinding against the rotor. It is recommended to have your brakes inspected and by a reputable and trustworthy shop.  To schedule reliable service with a CarAdvise Certified Shop, click here.

Squealing

If you notice a high-pitched squeal when you step on the brake pedal, it’s a clear sign that your brakes need to be replaced or at the very least, inspected. Brake pads are often equipped with wear indicators in the pad to produce this sound to let the driver know that brake service is needed.

Other factors that can create a squealing sound from the brakes include a build-up of brake dust on the brake pads, debris/ rust on the surface of the rotor or the brake pads becoming glazed over from high heat conditions. Due to the multitude of possible causes, including improper installation, or poor surface contact with the rotor, it’s recommended to have your brakes inspected by a CarAdvise Certified Shop when you hear squealing.

Loss of pressure when stepping on the brake pedal

When step on the brake pedal, you should feel a firm response that becomes firmer as you press down harder. If you own a later-model vehicle, a brake pedal that feels spongy or that can be pressed all the way down to the floorboard can indicate several possible causes.

It could be a relatively minor problem such as a leak or gap in the brake lines allowing air to enter creating diminished braking power, the brake pedal may need to be adjusted, or it may be something much more serious such as a failing brake system. If any of these are occurring, have a brake system inspection performed by a reliable car care professional through CarAdvise.

Pulsing or vibrations when the brake pedal is depressed

Feeling pulsing or vibrations when you step on the brake pedal typically means that the brake rotor is warn or warped. Braking power requires that the brake pads and brake rotor come into contact cleanly.

Pulsations or vibrations should not be confused with a vehicle’s anti-lock braking system, which prevents the brakes from locking when heavy brake pressure is applied through the pedal, particularly in slippery driving conditions such as rain, snow or ice.

A rotor that is warped by friction or heat, or that is worn beyond acceptable limits, can create vibrations or pulsing; it’s an indicator that you should visit a brake specialist or auto service center as soon as possible. To schedule brake service, choose a CarAdvise Certified Shop.

Types of brake repairs

The type of brake service a vehicle will require can vary depending on the problem, but there are a few routine brake services that are a part of routine maintenance.

Brake pad replacement

One of the most simple and most cost-effective brake repairs is replacing the brake pads. Replacement brake pads for common non-luxury vehicles frequently cost less than $300 per axle. Be careful to select a reliable mechanic, as improper installation of brake pads can cause some of the symptoms noted above.

Rotor resurfacing

If possible, it’s a good idea to consider resurfacing or “turning” the rotor when it is time to replace the brake pads. Since the vehicle’s brake stopping power relies on the rotor and brake pad coming in contact cleanly, a rotor that is scored or worn should be resurfaced.

Brake rotors include wear indicators that show if there’s enough material left to be resurfaced. A mechanic can also measure the thickness of the rotor against the manufacturer’s recommendations. If there’s enough material remaining, a technician will machine the rotor on a special lathe to remove just enough material away to create a new smooth rotor surface. If there’s not enough material remaining on the rotors, they will need to be replaced.

Other adjustments

Since braking systems rely on multiple interconnected components from the brake pedal all the way to the pad and rotor, it’s important to find a trusted, experienced mechanic who can make recommendations and adjustments to the brake system when needed. To schedule brake service with a trustworthy and reliable mechanic, choose CarAdvise.

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