Brake rotors are widely used with other brake components to slow down and stop your car. Yet how many rotors does a car have?
Let’s explore the answer in our article, which will offer comprehensive insights into their types, symptoms, and other related details.
What Is A Rotor?
A reliable brake system is of paramount significance if you want to disengage the clutch safely.
In numerous models, various components are connected to ensure smooth operation and maximize the drivers’ protection when it comes to emergency braking.
Among them, one of the essential parts is a rotor. Its main function is to utilize the friction force to slow down the sudden steering of a vehicle, averting the dangerous scenario of turning over.
More specifically, rotors start working once you place your foot on the brake pedal.
When you encounter a road hazard and press the brake, its internal pads would, in turn, compress the force toward the rotors.
Friction is consequently applied with the prospect of halting the wheels’ rotation.
During this process, lots of heat is generated, so a rotor is often made of steel, which is able to resist heat effectively. It is also equipped with gaps and ribs as an outlet for intense heat to escape outside.
Once you remove your foot from the brake pedal, its pads will stop burdening stress on the rotors.
You may find it easier to drive your car since no obstruction hinders the wheel’s movement.
How Many Rotors Does A Car Have?
Most modern automobiles have four rotors, each attached to a car wheel to heighten the braking effectiveness. Concerning the old models, many are not added with rotors but only drums.
Some have two rotors installed on the brake drum and front wheel because these two positions endure the greatest force when your car is shifting its direction.
What Are Some Brake Rotor Types?
There are several types of rotors on the market. It is advisable that you are clear about these types to purchase the most appropriate one for your automobile.
In this post, we only introduce four crucial kinds below.
Blank & Smooth
This is the most common type of rotors, widely used in standard sedans. Their design follows a basic and simplistic style with two distinctive colors: black and white.
Regarding their quality, many products nowadays are manufactured from recycled steel, which does not ensure optimal performance, unlike the original or OEM rotors.
They might have an extended lifespan thanks to thicker fins and upgraded materials.
Drilled
The drilled rotor has a load of holes on its surface to reduce extra heat and create a pathway for water and dust to escape so that your single rotor and overall braking system are less susceptible to the clogging issue.
Hence, this type is trusted by many drivers living in wet climates and passing through inclement terrain. But, its use is not recommended at a hot temperature.
Slotted
As its name suggests, the slotted model is equipped with several slots surrounding the external surface of a rotor.
This installation method helps your car stop more efficiently than the addition of holes like the drilled type.
For that reason, its usage is commonly preferred in heavy-duty SUVs or trucks, as they require more forceful braking power than a typical sedan or four-wheel drive.
Drilled & Slotted
This rotor is a combination of drilled and slotted types. It has both holes and slots around its surface.
Thanks to these features, its capacity to be immune to excess heat, water, and dirt will be likely boosted, and it helps brake your car more sharply as well.
This type is often used in high-performance vehicles, like race cars, requiring top-tier heat reduction and cooling to reap the best performance.
What Are Some Warning Signs Of A Bad Brake Rotor?
Following are some symptoms hinting at damaged rotors. If you spot one (or more), bring your car to a repair shop for a checkup and brake repair.
Vibration In The Steering Wheel
As we have mentioned earlier, a great amount of heat can be created during the braking process.
This could lead to rotor deformity, shown by the bent and uneven appearance. Over time, it would be on the fritz.
If this situation persists, the feeling of vibration will transmit to the steering wheel via the spindle. Then, you could sense some shaking movements when driving.
Pulsating Brake Pedal
The root of this problem is similar to the first symptom in the list. The sole difference lies in the vibration transmission, to the brake pedal in this case.
To avoid this from arising, you should try to avert the premature warping of your rotors, which is mainly attributed to excessive heat.
You could use rotors made up of other heat-resistant components, including stainless steel or ceramic.
Screeching Noise During The Installation Of Brake Pads
Even though a new brake pad needs a while before settling, a high-pitched noise after installation is unusual.
This sound could denote that your rotors are glazed or one of its edges is burnt due to intense heat.
You can check whether your rotor fails or not by crawling under your car with a flashlight.
If you notice some dark ring-like circles on its outside surface, there is a high chance that you need to replace it.
Cracked Rotors
When you spot some cracks in your rear rotors, they are subject to extreme temperatures for a long time.
These gouges are one form of surface dent that warn your rotors are out of order, and you should make a replacement with new ones.
Blue Discoloration
Blue marks are clear additional signs, showing something abnormal with your rotors, such as faulty brake calipers, uneven wear, and rotor cracks.
The discoloration is often rendered by misaligned calipers, brake defection, or insufficient heat dispersion, primarily controlled by rear brake components.
Corrosion
The rusting phenomenon is no stranger to many people, and the rotor is also prone to damage, as it is mainly manufactured from steel.
The situation could be exacerbated once you leave it outside, especially on cold days when the moisture ratings surpass the threshold.
Irritable Chemical Fumes
If you smell chemical odors from your automobile, the calipers are inclined to malfunction.
Under this circumstance, much stress is burdened on the rotors, causing them to warp and become off-balanced.
Popping Noise When Applying Brakes
When you press the brake pedal, a popping brake noise may emit from your vehicle, denoting that it runs into some problems. There is a likelihood that your pads have already worn down.
The contact between the metal backing plate and the rotor surface could be induced, and the unusual sound may stem from this interaction.
Wobbling Or Rotor Runout
Wobbling might indicate the problem of damaged wheel bearings (you can hear the wheel bearing noise when braking).
This issue only occurs when you drive over 70 mph, resulting in warped rotors and serious wear to the brake pads.
So pay attention to your driving style (driving slowly) to prevent brake issues.
Frequently Asked Questions
How Long Does A Brake Rotor Last
The answer varies greatly, depending on the make and model of your rotors. On average, a rotor may show signs of damage after two or three sets of brake pads.
However, the rotors’ exact lifespan in some sports cars or heavy-duty trucks is shortened because they have to suffer from more pressure and heat.
When Should You Replace Your Rotors?
There is no specific timeline for when you need to replace your worn rotors.
You only need to undertake this practice when they are vulnerable to damage with some outstanding signs, like cracking, warping, vibration, or grooving.
You should tow your car to a reliable motor workshop for routine brake maintenance from time to time. And certified mechanics will execute the brake inspection and rotor replacement for you.
How Could You Check Your Rotors?
Here is an all-inclusive tutorial for you:
- Step 1: Park your car and turn the engine off.
- Step 2: Use the jack and jack stand to lift your automobile.
- Step 3: Use a wrench or a plier to loosen the nuts and bolts.
- Step 4: Remove the brake calipers, pads, spark plug, and rotors from your car wheel.
- Step 5: Inspect your rotors carefully by glancing at the outer and inner edges.
- Step 6: Apply the same procedure to examine the brake pads, calipers and spark plug.
- Step 7: Clean them thoroughly by using a soaping mixture.
- Step 8: Place them back in the old positions and slowly remove the jack and jack stand.
The Bottom Line
Hopefully, our article helps you learn more about rotors and offers a satisfying answer to the question: How many rotors does a car have? You will find 4 rotors in modern cars most of the time.
Thanks for your support, and have a nice day!