We rely on our cars for many things; taking us to work, taking children to school and back home, running errands and buying groceries, not to mention trips to the gym, vacations, or even trips to the airport.
With all that coming and going, this means that the brakes on your vehicle are constantly being used. Even if you do a great deal of freeway driving, the brakes still get a good workout. With time, the brake pads will wear down far enough that they need to be replaced.
In some instances, however, your mechanic may tell you that, in addition to brake pads, your car needs new brake rotors.
What are brake rotors and why do you need to replace them? We are going to talk all about brakes and rotors in this article, so you won’t be scratching your head when the mechanic brings you the news.
What are Brake Rotors?
Depending on the type of rim your vehicle has, chances are that you can see them when your car is parked. If you see what looks like a large metal plate, platter or disc, that part is the brake rotor. The brake pads on your car are pressed against the brake rotor, sometimes called the brake disc, to stop the car. Depending on your year and model, you might have rear disc brakes as well.
While brake pads will wear out faster than a brake rotor, over time, the brake rotor will wear down far enough that it will need to be replaced.
Reasons Brake Rotors Must be Replaced
As you can imagine, rotors are a vital part of your vehicle’s braking system. Every bit as important as the brake pads.
Brake rotors need to be replaced for several reasons, including:
- They are too thin. Over time, the rotors do wear down and when they get to be a certain thickness, they will need to be replaced.
- If the brake pads become very worn, the metal backing plate can rub against the rotor, damaging it beyond repair.
- The rotors are too warped to be machined smoothly
If it seems as though you are replacing rotors on your newer car more often than your older model, this is because manufacturers need to make cars lighter every year to meet federal and state mileage standards. Making brake rotors thinner, along with other measures, is one way to make the vehicle lighter. Thinner rotors, of course, mean that you will need to replace them more often.
What is “Machining” Brake Rotors?
Even when you replace the brake pads promptly, everyday wear and tear and heat can cause the rotors to become uneven. Your mechanic will remove the rotors and put them on a machine called a lathe. The lathe will remove a very small amount of metal from the rotor, making it as smooth as the day your car came new from the factory. This is called machining the rotors or it is sometimes referred to as turning the rotor.
In addition to everyday wear, every time the brake pads are changed, the rotors should be machined to keep your new brake job quiet and working properly.
Although the lathe removes only a thin layer of metal, over time, this will cause the rotor to become thinner and thinner. All manufacturers have what is called minimum thickness levels. Once the rotor becomes thinner than what the manufacturer has allowed, the rotor must be replaced.
Even new rotors out of the box are often machined to ensure that they are 100% flat and even, to keep your brakes working properly.
What if I Use Rotors that are Too Thin?
For many reasons, some people simply don’t want to replace brake rotors when they are too thin. They may even have a mechanic just install new brake pads because the “rotors look fine.”
Driving with brake rotors that are extremely worn will not only make noise, cause the brake pedal or steering wheel to feel strange, but they also create a dangerous situation.
Brake rotors that are too thin are not able to absorb and then dissipate the tremendous amount of heat that brakes create regularly.
If you have ever seen brake rotors that have a pretty blue color to them- that is not some aftermarket cool looking brake rotor, that is a rotor that is too thin and it got so hot that the rotor changed color. The braking system could have other issues, but that is a sign of an overheated rotor.
Signs That Your Car Might Need Replacement Rotors
Most cars give you warning signs that the brake system needs to be looked at. Some important things you might notice when the brake pads or rotors need to be replaced include:
- Pulling to one side when braking
- A vibration in the steering wheel
- Brake fade (This is when you step on the brakes but the pedal sinks to the floor or the car takes a long time to slow down and stop)
- A pulsation in the brake pedal
- A grinding, screeching, or growling noise when you brake
Of course, there are other problems in the braking system that can cause these problems. A brake caliper, which holds the brake pads and presses them against the rotor, can become sticky and wear out one brake pad, even causing damage to the rotor.
Safety Matters
You want to keep safety in mind whenever it comes to repairing your vehicle. Brakes play a huge part in the overall safety of you, your passengers, and everyone else on the road. Don’t play games when you notice a problem or a noise coming from your brakes.
You can trust the ASE certified mechanics at My Mechanic to do a complete inspection and repair on your braking system, so you can drive with confidence, regardless of your destination.
