In order to drive your car safely, you have to have a reliable braking system. Modern vehicles use several components in conjunction with one another to successfully slow and stop moving cars, especially when they travel at high speeds.
Brake rotors are some of the most essential components in braking systems. Let’s take a closer look at what rotors are, what they do, and the different types of rotors you can find if and when you need a replacement.
What Are Brake Rotors?
Brake rotors are circular metal discs attached to each wheel of a vehicle, which work in conjunction with brake pads to create friction and slow down the car when the brake pedal is pressed; essentially, they are the spinning discs that the brake pads clamp onto to stop the vehicle.
In a disc brake system, brake pads and rotors work together to make the braking process possible.
When you press down on the brake pedal, it sends a signal via the master brake cylinder to your calipers to squeeze your brake pads together against the rotors’ large surface area.
This friction created by the pads pressing up against the rotors resists the wheel’s spin, which slows its rotation and halts the car’s movement.
When that happens, you’ll need to replace these parts with new rotors to keep your brake system up and running.
How Do Brake Rotors Work?
The brake rotor is an iron disc connected to the tire’s hub that is used in a disc brake assembly. Disc brakes are mostly used on the front wheels of vehicles, but they have increasingly been used on rear wheels as well.
Rotors work hand-in-hand with brake pads to stop your vehicle. When you step on your brake pedal, your vehicle’s brake pads are compressed against the rotor creating friction.
This friction enables your vehicle to stop while also creating a tremendous amount of heat. Rotors consist of two iron discs connected by ribs. When the brakes are applied, the brake pads are pressed to both iron discs.
There are many different rib designs for rotors, but they all do the same thing. They aid in dissipating the large amounts of heat created by the friction between the rotor and brake pads.
These ribs allow the hot air to vent from the rotor and also direct air in to cool the rotor. It is very important for rotors to be able to dissipate the large amount of heat so they can work properly.
What Are The Different Types of Brake Rotors?
When the time comes to replace your rotors, remember that not all rotors are made the same.
In fact, there are four different types to choose from, so before replacing your vehicle’s rotors, make sure you’re selecting the right one for your needs.
The four different rotor types are:
- Blank & Smooth – Blank and smooth rotors are what you’ll find on most passenger vehicles and feature a smooth, blank metal surface around the rotor.
- Drilled – Drilled rotors feature drilled holes around the metal surface.
- Slotted – Slotted rotors feature long “slots” or lines in the metal surface.
- Drilled & Slotted – Drilled and slotted rotors combine the drilled holes and slots for enhanced performance.
Luckily, choosing the right rotor for your vehicle is as simple as viewing the existing rotors on your vehicle.
Another thing to keep in mind when replacing your vehicle’s rotors is that the rotors on your family sedan will only work on your pickup truck and vice versa.
Now, let’s look at the different rotors, what they look like, and their respective applications.
Blank & Smooth (Original Equipment-Specific)
Blank and smooth rotors are what you’ll commonly find on most new passenger vehicles. Keep in mind that oe-specific rotors have a basic and premium option, which all depends on how they’re manufactured.
Unless you’re a super aggressive driver or you’re driving a luxury vehicle, blank rotors are a great choice for your vehicle.
Basic oe-specific rotors are traditionally made from recycled steel and often don’t perform as well as your original equipment manufacturer (OEM) rotors due to thicker internal fins, which in turn impact the cooling abilities of your rotors.
If you will use premium ceramic brake pads with your new rotors, don’t pair them with a basic set of rotors. Basic rotors will also reduce the life of your new pads, as they’ll wear down quicker due to the increased heat.
Drilled Rotors
Drilled rotors have holes drilled throughout the surface. These holes allow water, dust, and heat to easily dissipate off the surface of the rotor. Drilled rotors are an excellent choice for drivers that live in wetter climates, as they’ll help increase stopping power in wet, rainy conditions.
If you’re looking at drilled rotors for a performance vehicle, you’ll want to stay away. Drilled rotors don’t work well under high heat and can fail quickly in a race-type driving scenario.
Slotted Rotors
Slotted rotors feature slots around the exterior surface of the rotor. They’re a great choice for heavy-duty trucks and SUVs, especially those that need improved stopping power when towing or hauling.
The slots are designed to draw more air in between the pad and rotor surface, which improves cooling and heat dispersion.
They’re also designed to help remove excess brake debris and pad glaze that can occur at higher temperatures. While they are more efficient in a few ways, they come with the downside of not lasting as long, which also affects the life of your pads.
Drilled & Slotted Rotors
Lastly, drilled and slotted rotors are primarily designed for performance vehicles, like sports cars, that need enhanced cooling and heat dispersion. This rotor was designed to improve braking at high speeds during racing or track days.
Where there is friction, there is heat. Over time, the continual force and heat with off-road or track driving can sacrifice the integrity of your rotors.
To minimize the adverse effects of high-performance driving, drilled and slotted rotors have both tiny holes and small trenches etched into the surface, acting as gutters for water and heat.
While great at dissipating heat, these performance rotors also have some setbacks, the largest being durability. Because the material has been removed from the surface, the edges can wear away brake pads faster than traditional smooth surfaces.
The removed material also decreases the heartiness of the rotor, making them more prone to cracks.
Do Rotors Wear Down?
A new rotor has a smooth and even surface. As the brake pad makes contact with the even rotor, you’ll enjoy smooth braking performance. Over time, your rotors can lose their smooth finish. Worn rotors result in increased stopping distances and diminished braking performance.
Common Causes of Worn Rotors
- Sudden Stops: Panic or emergency braking at high speeds can cause rotor wear. The friction from the brake pad grabbing the rotor can cause high enough heat to result in wear.
- Riding the brake: Constantly hitting your brakes can result in a buildup of excessive heat that may lead to wear. When driving down a hill consider switching to a lower gear rather than riding your brakes on your way down.
- Worn Brake Pads: Driving too long on worn brake pads can cause rotor damage. As the brake pad wears down, the metal becomes exposed leading to metal-on-metal contact when you apply the brakes. This harmful contact between the pad and rotor can cause deep grooves to develop in the rotor.
Signs of Worn Rotors
Rotors are durable, but like other parts on your vehicle, they need to be replaced periodically. Driving on damaged rotors is dangerous; it can lead to increased stopping distances and a loss of braking power.
If you notice any of these symptoms as you drive, it’s time to make an appointment with your mechanic:
- Vibration when braking
- Squeaking, grinding or squealing noises when braking
- Grooves worn into the rotor
Replacing Brake Rotors
It’s a good idea to replace your rotors from time to time. Brake rotor replacement is a necessity since braking at all will, over time, wear down the steel surfaces of the rotors and the brake pads as well.
As these components wear down, your braking responsiveness and reliability will also decrease, leading to dangers when driving.
Make brake rotor inspection a regular part of your yearly car maintenance. Or take a look at your brake rotors yourself from time to time. You’ll also likely feel when your rotors are starting to suffer in performance, as your braking will seem less responsive and immediate.
Brake Rotors Replacement Cost
The average cost for a Brake Rotor Replacement is between $321 and $412. Labor costs are estimated between $94 and $119 while parts are priced between $227 and $293.
This range does not include taxes and fees, and does not factor in your unique location.
Factors affecting the price:
- Vehicle make and model: Luxury or larger vehicles may have more expensive rotors.
- Part quality: Aftermarket rotors are usually cheaper than OEM parts.
- Labor costs: Different repair shops may charge varying labor rates.
- Front vs. rear brakes: Replacing only the front or rear brakes can be cheaper.
- Whether pads need replacing too: A complete brake job including pads and rotors will cost more.
Related repairs may also be needed. You can also purchase rotors for a little cheaper and do the maintenance yourself, but only if you have the experience.
Summary
Brake rotors are important components in your car’s overall braking system. Be sure to pay attention to how they perform and how responsive your braking action is so you can replace them when necessary.
Don’t hesitate to ask a mechanic which rotor type is best for your vehicle and driving habits when picking out new rotors.