Modern disc brakes are far superior to older drum brakes in many ways. They offer better stopping power, and can be equipped with antilock technology to enhance your safety. However, they do have a few drawbacks. One of those is that pads wear out more quickly than shoes (pads are used on disc brakes, while shoes are used with drum brakes). With that being said, if you’re experiencing unusually fast brake pad wear, there could be a problem.
How this system works:
Your brake pads are the point where all the action happens with your system. They’re prone to wear and tear through normal operation. Understanding how disc brakes work isn’t all that hard, and the basics of the system are pretty simple.
A standard disc brake setup consists of a caliper, two brake pads and a disc, also called the rotor (per wheel). Fluid is sent to the caliper from the master cylinder when you press the brake pedal. A piston inside the caliper is activated, and the caliper then squeezes the rotor between the inner and outer brake pad. This slows down your car. It also creates friction, heat and lots of wear on the material of the brake pad.
Over time, brake pads wear out. That’s only natural. You have to replace them periodically. The exact frequency will depend on your driving style and habits. For instance, if you do a lot of stop-and-go driving, you can expect your pads to wear out much faster than a driver who does mostly highway or interstate driving.
With that being said, if you’re noticing abnormally fast brake wear, there could be some issues.
Common reasons for this to happen:
- Driver Error: The single most common cause of abnormally fast brake wear is driver error. This is most usually seen with “two-footed” drivers who use their right foot to work the accelerator and their left to work the brake. These drivers tend to leave their left foot resting ever so slightly on the brake pedal. Understand that ANY pressure on the pedal engages the brakes. So, even a small amount of pressure on the corner of the pedal is enough to put the pads in contact with the rotor while the car is moving. This eats through pads very quickly.
- Corroded Slide Pins: The caliper must be able to slide smoothly and evenly at all times. If the slide pins are corroded (most common on old cars, or flood-damaged vehicles), the caliper may not slide out evenly, leaving it sitting slightly off center. This keeps part of the pad in contact with the rotor at all times and will result in premature pad replacement.
- Abnormal Rotor Wear: In a normal brake system, the surface of the rotor should be smooth, and both sides should have equal thickness. However, if the rotors are worn, grooved, pitted, burnt or have seen significant wear (and are now in need of replacement), they can create rapid pad wear. It can also cause brake pads to crack, wear strangely (grooving) and other problems.
- Using Cheap Pads: You’ll find replacement pads available for a wide range of prices, and the natural inclination is often to go for the lower priced option. However, cheap pads generally don’t last very long. In addition, some very cheap pads can contain chunks of metal that will eat into your rotors. Avoid low-quality pads, even if it means paying a little more.
- Torn Piston Seal: Pistons are operated by brake fluid, but if the seal is broken, fluid will leak out. Additionally, the piston will not be able to return to its starting position completely, maintaining some degree of contact between the pads and the rotor, accelerating wear significantly.
How important is this service?
If your brake pads are wearing out prematurely, it can be expensive, frustrating and dangerous. Without reliable brakes, your car is not safe to drive. Your brakes should be inspected during routine maintenance, and you should be aware of their condition at all times.