Jul 27

Disc Brakes Squeaking & Rotor Damage | Basic Guide Pt 1

Disc brakes squeaking is but one small issue in the grand-scheme of brake rotor damage but for many novices, its the first indication when their attention is needed.

The truth is, only a handful of us possess the enthusiasm that would allow us to tackle every mechanical problem with confidence. And it doesn’t matter if you’re a noobie or the Tim the Toolman Tinkerer, sometimes its just plain difficult to spot the cause of damage.

Many non-enthusiasts who are first time car buyers are unsure of this occurance and start anxiously lurking forum threads to find answers

disc Brake damageSo we put together this quick and short article so you’ll have a solid foundation of the various types of brake rotor damage like disc brakes squeaking, cracking, rusting or anything else that has caught your attention. You’d be surprised that some things are absolutely normal and not life-threatening.

FYI – we’ve tailored this post so a beginner would feel comfortable reading without any hindrance. If you already know all of this, then good for you!

1. Brake Rotors Rusting
In almost every automative forum, there would lay the question of brake rotors rusting. Many non-enthusiasts who are first time car buyers are unsure of this occurance and start anxiously lurking forum threads to find answers. Well lurk-no more!

The majority of the component materials that make up your brake rotors is cast iron. Therefore, due to the mere oxidation, rust will inevitably develop. This explains why rust will still occur even if you live in the city and only take your car out on weekends. A build up of rust is not life threatening nor is it the cause of your disc brakes squeaking, so relax.

2. Brake Rotors and Brake pedal pulsation

Many of today’s vehicles have brake systems where the disc rotors are a “top hat” design; These designs are generally easier to service but at times, can create some customer dissatisfaction due to brake pedal pulsation during the brake application.

Brake pedal pulsation is most often the result of disc thickness variation in the rotor. Disc thickness variation (DTV) is the technical term for a rotor that is not uniformly thick.

Quality rotors are uniformly thick when new, and will stop the vehicle smoothly. However, due to other potential irregularities in the braking system, disc thickness variation can develop over time and eventually lead to brake pedal pulsation.

DTV = Pulsating Brake Pedal (and, in extreme cases, severe mechanical vibration through the entire vehicle)

The most common cause of DTV is rust scale or debris between the hub and rotor mounting surfaces, This causes the rotor not to sit flat resulting in excessive runout.


Ok guys, that’s it for the 1st Part. The 2nd installment will be posted in a few days! Stay Tuned and remember to add DBA on Facebook!