7 Causes of Uneven Brake Pad Wear (+How to Fix)

Picture this:
You’re driving along when the approaching traffic light turns red. You push the brake pedal to slow down, but alarmingly, your car pulls to the side without any steering effort.

This worrying issue is a likely symptom of uneven brake pad wear — often caused by caliper failure or warped rotors. You’ll need to get it fixed ASAP to avoid veering off course.

Luckily, we’ll help you stay ahead of the issue by explaining the common causes of uneven brake pad wear, how to fix them, and when you should have your brakes checked.

This Article Contains:

Is Uneven Brake Pad Wear Normal?
7 Causes and Solutions for Uneven Brake Pad Wear
Can You Change the Brake Pads on One Side Only?
What Are the Common Brake Pad Wear Patterns?
When Should You Get Your Brake Pads Checked?

Is Uneven Brake Pad Wear Normal?

No, uneven brake pad wear between your vehicle’s right and left sides means one brake is working harder than the others, indicating a problem with your braking system.

Meanwhile, it’s normal for your front pads to wear out quicker than the rear brake pads. That’s because braking shifts the weight of your car forward, placing more stress on the front brake pads as they work to reduce your vehicle’s momentum.

However, in some cases, traction control and stability systems can cause the rear brakes to engage more frequently. This wears out the rear pads faster since they are often thinner than the front ones.

Now, let’s look at the finer details behind uneven wearing on your brake pads.

7 Causes and Solutions for Uneven Brake Pad Wear

Here are the main culprits behind your brake pad issue:

1. Disc Thickness Variation

Disc Thickness Variation (DTV) is a condition where your vehicle’s brake rotors have different thickness levels.

How does that happen?
Sometimes parts of the rotor are flatter or rougher than others due to rust, frequent slamming on the brakes, debris, or a sticking brake caliper. The brake pad scrapes over these spots more aggressively, leading to uneven, accelerated pad wear in specific areas.

The fix: Have a mechanic iron out the flat spots and clean the rotors with a brake cleaner before reinstalling them. This will remove any brake pad dust or rust, which are the major contributors to brake wear.

However, rotors have a minimum thickness threshold. Once they’re worn beyond that limit, resurfacing won’t work, and you’ll need a brake rotor replacement.

If the brake rotor and pad are worn beyond repair, you should also get your caliper piston and its rubber boot inspected. If they fail to retract properly, it will lead to uneven pad pressure and brake wear.

2. Caliper Failure

The brake caliper has a piston that pushes the pads against the rotor to stop your car. But if the rubber seal that pulls the piston back wears out, it can’t do its job.

The result?
The pad keeps rubbing against the rotor nonstop — leading to premature brake pad wear and potential overheating.

Sometimes, rust or debris on the caliper can also lead to sticky caliper pistons This means the piston won’t slide efficiently, increasing brake pad wear.

The fix: Have an expert look at your brake caliper, and if needed, you can get it rebuilt or replaced.

3. Corroded Slide Pins

A sliding pin (guide pin) allows the brake caliper to slide back and forth, ensuring the brake pads press evenly on the rotor.

But when a sliding pin becomes corroded or if a piston is stuck, the caliper can’t slide smoothly. As a result, the brake caliper gets stuck in one position, leading to uneven or accelerated brake pad wear.

The fix: Use a wire brush and grease to remove the corrosion. If the slide pins are beyond repair, replace them with new ones.

4. Misaligned Brake Pads

The correct alignment of a brake pad ensures that it squeezes the rotor evenly. However, improper pad installation can lead to a misaligned brake pad and uneven pad wear.

If you have a misaligned brake pad, you’ll notice braking issues within weeks or months of the installation.

The fix: Call a mechanic to inspect the installation. They will hit the brake pedal and check if both the pads squeeze the rotor simultaneously. If not, they will realign them.

5. Corroded or Dirty Rotors

Sometimes, new rotors can experience brake pad wear due to dirt or grease that accumulates if you don’t drive your car regularly. Dirt or corrosion particles act like sandpaper, accelerating wear on the pad and the rotor.

The fix: Clean the rotors with a brake cleaner that leaves no residue after its solvents evaporate. You can also ask a mechanic to apply an anti-rust over the rotor during regular car maintenance to prevent rust.

6. Warped Rotors

A warped rotor has a deformed or wavy surface, usually due to a hot rotor coming in contact with cold water. When a brake pad comes in contact with a warped rotor, it only makes contact with the rotor’s high points, leading to uneven brake pad wear.

The fix: Avoid spraying water on your wheels immediately after a long drive and allow the rotors enough time to cool down.

7. Different Types of Brake Pads

Brake pads from different companies or different pad materials (ceramic vs. semi-metallic) will wear down at different rates. They may also vary in pad thickness.

While it might be okay to have brake pads made of different materials on the front and rear, you should avoid using different materials on the same axle.

The fix: Have a mechanic select and install the brake pads to ensure your vehicle has the correct pads.

Wondering about changing your brake pads?
Be sure to read the next section before doing so.

Can You Change the Brake Pads on One Side Only?

No, you shouldn’t install new brake pads on only one side, as this can lead to further uneven pad wear.

That’s because the new pad would be different in thickness from the old one. The difference in pad thickness could result in uneven pressure, stopping force, and wear. Rather, replace both front or rear brake pads together.

You understand why brake pads experience uneven wearing. However, you also need to understand how different problems cause different types of uneven brake wear. Let’s take a closer look.

What Are the Common Brake Pad Wear Patterns?

Here are the different types of pad wear and the reasons behind them:

A. Inner Pad Wear

Inner pad or inboard pad wear is a fairly common wear pattern. If your vehicle has a floating caliper brake system, it’s normal for the friction material of the inside pad to wear out faster than the outer brake pad. However, the difference between the pad wear shouldn’t be more than 2-3 mm.

If your mechanic finds inboard pad wear when inspecting a brake’s caliper, the most likely cause is a seized or faulty caliper pin (slide pin). It could also be from a stuck caliper piston due to a worn piston seal or internal corrosion. Sometimes, a fault in the master cylinder also leads to wear inside the pad.

To fix the uneven brake wear, a professional will inspect the hydraulic braking system and the caliper for residual brake pressure. They may also check the guide pins and piston boots for corrosion or damage and replace them.

B. Outer Pad Wear

It’s rare for the outer pad or the outboard pad to wear out first. For this reason, you hardly see wear sensors for the outer pad.

Wear on the outboard pad usually occurs when the outerboard’s friction material continues to rub against the rotor even after the caliper piston retracts. This typically happens due to faulty guide pins.

To fix this uneven pad wear, call a mechanic to service or replace the caliper guide pins and bushings or have a complete caliper rebuild. If the outboard pad wear is more than the recommended levels, you should get new brake pads installed.

C. Tapered Pad Wear

If the friction material on the brake pad is tapered or has a wedged pattern, it could mean:

The caliper has excess movement
One side of the pad is seized in the bracket
Corrosion under the abutment clip (metal clip that helps brake pads slide evenly) is preventing the ends of the pads from moving

A tapered brake pad wear pattern is normal in vehicles that have a small rear floating caliper on the rear brake. The brake pad manufacturer will likely specify the conditions for normal wear (rate, amount of tapering, etc.).

This uneven wear can also be caused by faulty installation or worn guide pins. In that case, you can get the pad reinstalled or buy a brake hardware kit to replace the caliper guide pin bushings.

D. Cracking, Glazing, or Lifted Edges on the Pads

Brake pad overheating can cause cracked, glazed, or lifted edges of the friction material. The high temperatures occur due to excess friction from brake overuse, a defective pad, a stuck parking brake, or a malfunctioning caliper.

As a result, the pad’s raw components can break down, which can even start to separate the brake pad from the backing plate (the mounting for the brake pad’s friction material).

You can fix this kind of brake pad wear by replacing and installing a new pad correctly in your disc brake. When you do so, you should also get your parking brake adjusted if it’s on the affected wheel.

Uneven brake pad wear is concerning, as it often results in reduced braking ability. So, you’ll need regular inspections to ensure your brakes are in good condition.

Read on to discover how often you should get this service.

When Should You Get Your Brake Pads Checked?

You should get your brake pads checked every 50,000 miles. However, contact a mechanic earlier if you notice these specific symptoms of brake pad wear:

Difficulty in braking
Shaking steering wheel
Stopping your vehicle takes more time than usual
Your vehicle’s nose pulls to one side on braking (uneven braking)
Your brake squeals or gives a faint scraping or buzzing sound whenever you hit the brake pedal
You get a clicking sound whenever you push or release the brake pedal

Certain electronic braking systems also have abnormal brake pad wear rates because the rear brake controls the nose dive. If the wear is sooner than expected, you should get the brake system inspected or book a complete brake service.

Restore Your Brakes to Optimal Condition with AutoNation Mobile Service

Uneven wear on your brake pads is a dangerous problem that results in reduced or uneven braking.

To ensure your safety on the road, you should regularly inspect your brakes. Also, get a brake pad replacement as soon as you notice problems, like a shaking steering wheel or brake noise.

Don’t want to drive to a mechanic with compromised brakes?

AutoNation Mobile Service will repair the brakes from your driveway. We’re a mobile auto repair service that provides convenient online booking and a 12-month, 12,000-mile warranty on all repairs.