6 Causes of Uneven Brake Pad Wear (Why is One Side Thicker?)

Last Updated on June 14, 2021

Every disc braking system relies on brake pads to create the necessary friction needed to slow down the vehicle. The brake pads are positioned within your brake calipers.

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Whenever you step on the brake pedal to slow the vehicle down, the brake pads will press against the spinning disc brake rotors and create friction. The friction material on the front of the brake pads is made to be used up over time. In most circumstances, the brake pads will wear down evenly on both sides of the vehicle no matter what type of brake pad you use.

However, there are situations where the brake pads may wear unevenly on each side. A lot of car owners get confused about this and are unsure why this happens.

Whenever you have uneven brake pads in your vehicle, you will be forced to replace all the brake pads at the same time. This can be an unnecessary expense since you’ll end up replacing pads which are still good and not completely worn out yet.

But you will need to do this because your vehicle must have brake pads which are equally worn. Otherwise, it could jeopardize the dynamics of your braking system and could possibly cause problems with braking itself.

See also:  Best Brake Pads for Your Car, Truck, or SUV

Top 6 Reasons for Brake Pads Wearing Unevenly

Below are six of the most common reasons for brake pads to wear out unevenly on each side of the vehicle.

Related: 7 Reasons Your Car Pulls to the Right or Left When Braking

#1 – Rotor Thickness Variation

brake rotor thickness measure

Disc thickness variation is a mechanical term which refers to when the rotors of a vehicle have different levels of thickness. Whenever there is a variation in the thickness level of your rotors, it will cause the brake pads to get worn out faster.

The rotors will have more flat spots that the brake pads will come in contact with. Once they do, the wear of the brake pads will become uneven on that corner of the vehicle.

#2 – Sticky Caliper Pistons

stuck brake caliper

If you some debris or rust on one or more of your pistons, then it can cause sticky brake calipers. This means that the piston won’t slide correctly, causing the brake pad to make constant contact with its corresponding rotor.

A stuck brake caliper will cause the brake pad material to be used up much quicker than the others.

#3 – Misalignment

brake pad lube

Sometimes when you have new brake pads installed in your vehicle, the mechanic might not align them evenly, sometimes due to a bent bracket on the back of the pad. Anytime you have misaligned brake pads, it will cause them to wear unevenly throughout the course of your braking activities.

You should notice this problem occurring within a few days of getting new brake pads that are misaligned. Once you start experiencing braking issues, you will wonder why your brake pads are acting up already when you just got them replaced.

Well, it is due to the brake pads wearing out unevenly because they are not aligned correctly in the caliper.

#4 – Dirty or Rusty Rotors

worn brake rotor

Dirty rotors are certainly one possible cause of uneven wear and tear of your brake pads. These do not need to be old rotors either. Sometimes when new rotors are installed in a vehicle, they might still have dirt or grease on them from wherever they were stored.

The rotors need to be cleaned with a formulated brake cleaner to ensure this debris is removed from them. Not only that, you may want to apply an anti-rust coating over the rotors to help prevent them from rusting. Easier said then done though.

#5 – Warped Rotors

best brake pads

A warped rotor means that the surface of it is not perfectly smooth, but slightly deformed or wavy. This usually happens when cold water makes contact with a scorching hot rotor.

When you have a warped rotor, the brake pad only makes contact with the high points of the rotor while the other pads make full contact. This results in uneven pad wear.

This is why you should never immediately spray water on your wheels and start washing your car immediately after some spirited driving. You want to make sure the rotors have been given enough time to cool down so they are simply warm to the touch and not hot.

To confirm, simply place your hand a few inches from the rotor. If you feel a lot of heat, wait a few minutes before using water.

#6 – Different Types of Brake Pads

cheap brake pads

It is important that you stay consistent with the type of brake pads that you install in your braking system. Do not use different brands or materials of brake pads because they are likely going to wear down at different rates and have a completely different lifespan.

If you stay with the same model and thickness in your brake pads, then you will have a better chance of them wearing evenly.


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