Brake rotors play a crucial role in your vehicle’s braking system. They work with the brake pads (in disc brakes) to create the friction needed to bring your car to a safe stop.
But like any other brake component, rotors can wear down over time.
Wondering when to replace brake rotors?
In this article, we’ll explain how rotors work, when to replace them, why they wear out, and how much a rotor replacement costs — so you can keep your brakes in top shape.
Let’s get started!
This Article Contains:
- How Do Brake Rotors Work?
- When to Replace Brake Rotors (6 Key Signs to Watch For)
- What Contributes to Brake Rotors Wear?
- Can You Resurface the Brake Rotors Instead of Replacing Them?
- Is it Urgent to Replace the Brake Rotors?
- How Much Does a Brake Rotor Replacement Cost?
How Do Brake Rotors Work?
Brake rotors (brake discs) are steel or carbon-ceramic discs attached to your car’s axles. They spin with the wheels and play a crucial role in slowing down your vehicle when you press the brake pedal.
Here’s how this brake component fits into your entire braking process:
- When you apply pressure on the brake pedal, a plunger in the master cylinder forces brake fluid into your brake lines.
- The brake fluid goes through the lines to your wheels and then to the brake calipers.
- The brake fluid’s pressure pushes on the pistons in the brake caliper, which in turn presses against the brake pads.
- The brake pads then rub against the brake rotor, causing your vehicle to slow down due to the friction created.
This system ensures smooth and controlled braking, making it a key component of your vehicle’s safety.
NOTE: Some cars use drum brakes instead of rotors in the rear brakes. In a drum brake, the brake shoes press against a drum to create friction and slow the vehicle.
But how can you tell when to replace the rotors on your disc brakes?
Let’s check out the warning signs your car will give you.
When to Replace Brake Rotors (6 Key Signs to Watch For)
Most steel and composite rotors are designed to last up to 70,000 miles. If you’re using a carbon-ceramic disc brake system, your rotor set will last longer than steel ones.
However, frequent hard braking or driving in extreme temperatures can cause your brake discs to wear out sooner.
When that happens, your car will send you the following distress signals:
1. Screeching
If you hear a high-pitched screech when you press the brake pedal, it’s a clear warning sign that something isn’t right. Excessive brake pad wear usually causes this sound.
However, screeching can also result from uneven brake rotor wear, where the surface becomes rough or warped due to excessive heat and repeated braking. Ignoring this noise can lead to further damage, poor braking performance, and a costly brake service.
2. Vibrations or Brake Pulsation
Imagine you’re driving down the road and come across a red light. You hit the brakes to come to a halt but feel a tight vibration on the brake pedal and steering wheel.
This pedal vibration can’t be good, right?
If your car vibrates when you brake (also known as brake pulsation), it may be a sign to replace bad rotors. This happens because of accumulated brake pad deposits on an old rotor. These deposits are brake pad material that collects on the face of your brake discs and creates uneven spots.
Brake pad deposits occur due to several factors — including a brake system subjected to excessive heat, incorrectly fitted pads, and uneven clamping due to seized brake pistons.
3. Grinding
Do you hear heavy metallic grinding noises when you’re applying the brakes?
Chances are, your brakes are heavily corroded.
When brake system components corrode, they tend to grind against each other — causing those loud brake noises.
The best way to prevent this brake problem is to pay attention to your pad wear indicator and replace worn brake pads. You can also check whether an old rotor needs replacing when you put in new brake pads or get a tire rotation.
4. Pulling
If your car pulls to one side when you apply the brakes, it could indicate worn brake pads or uneven brake rotor surface.
Over time, disc brakes can develop rotor thickness variations or warping due to excessive heat and friction. When this happens, the brake force becomes unbalanced, causing the vehicle to veer left or right instead of stopping in a straight line.
Other possible causes include uneven brake pad wear or a sticking brake caliper.
NOTE: The following two signs aren’t easy for everyday drivers to spot. Instead of trying to inspect your brake rotors yourself, we recommend taking your vehicle to a certified mechanic. They will conduct a thorough brake inspection to see what’s wrong.
5. Cracks
Brake rotors are constantly subjected to heavy heat, which can cause their surfaces to crack. There are two types of cracks that can occur on rotors:
The first, known as heat checking, produces small hairline cracks on the rotor’s friction surface. This type of cracking is expected, especially in high-performance scenarios, and doesn’t warrant a rotor replacement.
The second type of crack is a crack to the edge – indicating that the brake rotor is at the end of its life. You’ll have to immediately switch out these bad rotors to avoid further damage to your vehicle.
6. Damaged or Grooved Rotor
If you notice extensive damage or grooves on your brake rotor, it’s time to switch them out for a new rotor set.
When your brake pads wear out heavily, the metal backing plate and rotors come into contact — damaging the rotor surface. You should also watch out for road debris, rust, and corrosion that can damage your brake discs.
NOTE: A grooved rotor is not the same as a warped rotor. A warped rotor is an extremely rare occurrence.
Several factors contribute to rotor deterioration, and being aware of them can help you extend their lifespan.
Let’s take a look at the key culprits of this brake problem.
What Contributes to Brake Rotors Wear?
Your brake rotor wear is typically influenced by these key factors:
A. The Type of Brake Rotors Used
There are four types of brake rotors found on vehicles:
- Blank and smooth rotors: These are common in most vehicles and ideal for everyday driving, but wear out faster.
- Drilled rotors: These feature holes to disperse heat, dust, and water, making them great for wet conditions.
- Slotted rotors: This type features slots for better airflow, suited for SUVs and heavy vehicles. They cause faster brake pad wear but are more durable than blank rotors.
- Drilled and slotted rotors: This type offers top performance and durability but is the most expensive.
B. The Quality of Your Brake Pads
The quality of your brake pads can have a significant impact on the life of your brake rotors.
How?
Brake pads come in direct contact with your brake rotors all the time.
If you choose low-quality new brake pads during your brake pad replacement, it can wear out much sooner than usual. Once the brake pads wear out, the metal backing plate rubs against the disc, which causes increased rotor wear and damage.
C. Driving Style and Environment
Aggressive driving and frequent stop-and-go traffic can cause your brake rotors to wear out sooner than you’d expect.
But that’s not all you have to worry about.
If you live somewhere with extreme temperatures (really hot or cold climates), your brakes will suffer rotor damage sooner than under normal conditions. This happens because your brakes have to work harder to bring your car to a stop on icy or snowy roads. Moreover, exposure to road salt and moisture corrodes the metal on rotors.
Conversely, hotter temperatures cause inefficient heat dissipation from your braking system, leading to brake fade, which in turn requires more braking force.
D. Car Weight
If you drive a heavy vehicle like an SUV, expect a shorter brake rotor life than a lighter-weight vehicle.
The heavier a vehicle is, the greater the force needed to stop it. This can take a toll on your brake pads and rotors — and you’ll need to replace them more often.
E. Axle Positions
In most modern cars, the front axles usually carry a heavier load than the rear axles because the engine is mounted at the front, adding to the weight there. As a result, the brake disc set and other brake components in the front of the car usually wear out faster than those at the back of the vehicle.
That said, not every situation needs a rotor replacement.
Can You Resurface the Brake Rotors Instead of Replacing Them?
Resurfacing rotors can be a cost-effective alternative to replacing them, but only if:
- They have at least 0.050” rotor thickness above the discard limit.
- There is no heavy corrosion on the edges.
- The rotor surface is not excessively blued from overheating.
- Any grooves in the contact area are shallow and not too deep.
Resurfacing rotors can restore a smooth braking surface and extend the rotor’s lifespan. However, if you have excessively worn rotors, replacement is the safer option.
Now, if you’re contemplating whether you can delay this auto repair, we’ll tell you why it can be a bad idea.
Is it Urgent to Replace the Brake Rotors?
Yes, replacing a damaged or worn rotor is crucial for your safety.
If your rotors are excessively thin, warped, or heavily grooved, they can compromise braking performance, leading to longer stopping distances, brake fade, and reduced control. Ignoring rotor damage can also cause excessive wear on other brake parts, requiring a more expensive brake job later.
So, if you notice problems, such as vibrations, pulsation, or reduced braking efficiency, it’s best to book a brake repair service as soon as possible to ensure safe driving.
How Much Does a Brake Rotor Replacement Cost?
On average, a brake rotor replacement can cost anywhere between $310 and $470.
This estimate covers:
- Cost of a new rotor: $220 to $300
- Labor charges: $90 to $170
However, the final auto repair bill can vary depending on the local labor charges and your vehicle’s make and model.
NOTE: If you want optimal braking performance and longevity, replacing pads and rotors together is ideal. Brake pad replacement cost ranges between $115 and $320 per axle.
Restore Your Braking Efficiency with AutoNation Mobile Service
Brake rotors typically last around 70,000 miles, but factors like driving habits, road conditions, and rotor quality can impact their lifespan. Staying alert for signs of rotor wear and investing in high-quality parts can ensure optimal braking performance, keeping you safe on the road.
And if you don’t want to drive to an auto repair shop to swap out worn brake rotors, give AutoNation Mobile Service a try!
Our expert technicians can carry out a brake inspection and replace a worn rotor right from your driveway.
Just fill out this online form to book your brake service.