Common Failures Of A Brake Disc: Signs And Signs Of Defects!

This is a novel concept. Disc brake systems contain brake discs, which are also called rotors. Like brake pads, rotors are considered wear items that require periodic replacement. If you are not sure when it is time to change this component of the car, we have made a list of common brake disc failures for you here .

Some people argue that you don’t always have to service pads and rotors together. It’s well worth spending a little extra money on rotors, as your brakes are extremely important.

What is a brake disc?

It consists of a brake disc rigidly connected to the axle being braked and two or more non-rotating pads covered by a friction lining, which are pressed against the disc, usually by a hydraulic or pneumatic actuator.

Disc brakes are commonly used as the main brake on cars , rail vehicles, motorcycles, mopeds and scooters, displacing the drum brakes used in the past, as well as on bicycles, replacing shoe brakes (acting on the tire). They are also used in machine tools (for example, as brakes for the quick stop of the spindle of a machine tool).

Beginnings of brake discs

The development of disc brakes began in England in the 19th century. In 1902, the Lanchester Motor Company designed brakes that looked and operated similar to today’s disc brake system, in which the disc was thin and the pad was activated by cable. The use of this design began with success in aircraft before World War II and even the German Tiger tank was fitted with discs in 1942.

Compared to drum brakes, disc brakes provide greater braking efficiency, since the disc cools down more easily. Consequently, discs are less susceptible to brake fade, caused by overheating of brake components.

What is the function of the brake disc?

There are two different types of brake systems: disc and drum. As mentioned, disc brake systems rely on disc-shaped brake rotors for stopping power. All modern cars have front disc brakes and many have four wheel disc brakes.

The operation of the brake discs is simple. When the brake pedal is depressed, pressurized hydraulic fluid flows from the master cylinder and acts on the brake calipers . Each of the brake calipers contains a set of brake pads that press against the brake rotors, creating the necessary friction to stop your car.

Symptoms and common failures of a brake disc

Brake discs are simple components with a fairly limited list of common symptoms. Some of the most common signs and failures of a brake disc include:

1- Vibration or pulsation

Worn brake rotors often cause a pulsation or vibration when braking. The sensation is felt on the steering wheel or on the brake pedal.

Why is this happening? Rotors wear unevenly over time . As a result, the pads bounce up and down on the high and low points of the rotor surface.

2- Abnormal noise

Rotors with uneven surface wear may make a rattling noise upon contact with the pads. A clang may also be heard when the brakes are applied. This is one of the common brake disc failures that can be easily detected.

3- Wear higher than recommended by the manufacturer

The brake rotors and pads engage each time the brake pedal is depressed . Therefore, both wear out over time. That’s why the professionals measure the thickness of the rotors every time a brake service is performed.

If the rotors are worn beyond the manufacturer’s recommended minimum thickness, they must be replaced. This specification may be stamped on the front of the brake disc, or it may be found in your vehicle’s factory repair information.

4- Reduction of braking capacity

An uneven rotor surface can push the pads away from the rotor, creating excessive clearance between components and a low brake pedal.

5- Visible imperfections

Do the rotors have cracks, hard spots, deep scoring, or heat discoloration ? Then they definitely need to be replaced.

What to do if you think you have a bad brake rotor?

Don’t want to take any chances with your brakes? If you suspect you have bad brake rotors, diagnose and repair the problem immediately.

In some cases, a brake rotor with a rough or dull surface can be reconditioned, rather than replaced, to restore proper operation. But if a rotor is worn beyond specification (or machining would take it past that point) it should be replaced.

A rotor should also be removed if it has defects that cannot be corrected during the resurfacing process. Do not forget, that you should always change the rotors as a pair to guarantee optimal braking capacity.