Brakes

Why do they make loud noises sometimes?

First, one needs to understand that friction between metal (rotors & drums) and brake material causes a vehicle to stop. This friction can develop a vibration which is heard if it gets to the right frequency. There are several relatively successful ways to limit brake noise, like the use of shims or silicone behind the brake pads to dampen the vibration. The most common perception on brake noise is that something is wrong. This is because several manufacturers use a metallic wear indicator that rubs or squeals against the steel rotor when the fricition material gets low. The other noise many people have experienced is the brake pad or a shoe wearing down to the metal and grinding into the rotor or drum. Many drivers associate all brake noise with failure. However, frictional braking noise is a common occurence and can even come and go over time.

Why do brakes shake, vibrate or pulsate?

Ever try to warm your hands by rubbing them together? That’s heat from friction. A brake pad pushing against a rotor generates a tremendous amount of heat. Vehicle manufacturers have reduced the size of today’s braking components to save on weight and costs. Unfortunately, this prevents the brake system from dissipating heat rapidly. Heavy brake use increases the heat load, which can lead to warped drums and rotors. This condition is evident when you feel your steering wheel, brake pedal or the entire vehicle shake as you apply the brakes.

So can I still resurface my rotors?

When brake pads and rotors do their job under normal circumstances, the surface of the rotor can become grooved or ridged. Putting new pads together with a rough-surfaced rotor will accelerate the wear on those brake pads. It’s like taking sandpaper to a piece of wood. The rougher the surface, the quicker the brake pads will wear. New pads mixed with old rotors will also decrease the braking efficiency because less of the pad contacts the rotor.

Resurfacing is a process used to remove a layer of metal from a brake rotor. The area on which the brake pads contact the rotor is where the resurfacing happens. This process ensures a flat, even surface for the pads to grip the rotor. This results in eliminating pulsation and maximizing braking efficiency.

Vehicle manufacturers determine at what point a rotor is too thin to be resurfaced. They also designate a thickness at which a rotor should be discarded. Due to an inability to dissipate heat quickly enough, a thin rotor will warp more easily and diminish the braking efficiency (i.e. brake fade). Drivers who are heavy on their brakes- you know who you are- may experience rapid rotor warping even with a brake rotor that is within specifications. When a car comes in for brake service, we will inspect the braking system and tailor the repairs to your driving style.