7 Causes of Uneven Brake Pad Wear
Brake pads press against the rotating rotor to create the necessary friction when braking. Typically, you want even wear on both sides, regardless of the type of brake pads you use.
However, there are times when brake pads on both sides wear unevenly, requiring you to replace all of your brake pads sooner than expected. To avoid these unnecessary costs in the future, it’s important to find out what’s causing the uneven brake pad wear before it happens again.
The 7 Most Common Reasons for Uneven Brake Pad Wear
The most common reasons for uneven brake pad wear on both sides of your vehicle are:
1) Rotor Thickness Variation
Disc thickness variation is a mechanical term that refers to when the rotors on your vehicle are different thicknesses. Variations in rotor thickness will cause your brake pads to wear out faster.
Rotors have more flat spots where the brake pads contact. When this happens, you will experience uneven brake pad wear on that corner of your vehicle.
2) Sticky Caliper Pistons
Brake calipers can stick if one or more pistons are dirty or rusty. This means that the pistons do not slide properly and the brake pads are in constant contact with the corresponding brake disc.
3) Misalignment
In some cases, the mechanic may not position the new brake pads evenly on the vehicle. This may be due to a bent bracket on the rear of the pad. Misaligned brake pads will cause the brake pads to wear unevenly during braking.
You should notice this issue within a few days of receiving your new misaligned brake pads. When you start having braking problems, you’ll wonder why you just replaced your brake pads and they’re already causing problems.
4) Dirty or rusty rotors
Dirt on the rotors can certainly be the cause of uneven brake pad wear. It doesn’t have to be the old rotors, either. When you put new rotors on your vehicle, they may still have some dirt or grease on them from the installation process.
When you buy new rotors, they often have a gray paint-like coating on them to prevent rust. This coating can be removed with brake cleaner, but it’s not necessary.
5) Warped Rotors
When a rotor is warped, the surface is not perfectly smooth, but slightly deformed or wavy. This usually happens when cold water touches a red-hot rotor.
If the rotor is warped, the brake pads will only touch the highest points of the rotor, while the others are in full contact. This leads to uneven pad wear.
That’s why you shouldn’t spray water on the wheels right after driving at high speed, and you shouldn’t start washing the car right away. You want the rotors to have enough time to cool down so that they’re warm to the touch, not hot. To check this, hold your hand a few inches away from the rotor. If it feels very hot, wait a few minutes before using water.
6) Corroded or stuck guide pins
Another common cause is corroded or stuck guide pins. These pins help the caliper slide and press the brake pads against the rotor. Corrosion can occur when dirt or moisture builds up. This can restrict caliper movement and cause uneven brake pad wear.
To avoid this issue, regularly clean and lubricate the caliper guide pins. This will prevent rust from forming, reduce friction, and keep your brake pads in good condition.
7) Brake Pad Type
It is important to be consistent with the type of brake pads you install in your braking system. Do not use brake pads of different brands or materials. Different brake pads can wear at completely different rates and last very different lives. Using brake pads of the same model and thickness will increase the chances of even wear.