Is it safe to drive on warped rotors?
Warped rotors are relatively common, but that doesn’t mean they are okay to drive on
Rotors are an integral part of a car’s braking system.
Warped rotors can be dangerous to drive on.
Repair fees to repair or replaced warped rotors can start at approximately $200.
Rotors are the discs that brakes clamp down on to stop the wheels from spinning and to bring your car to a stop. Warped rotors are a relatively common occurrence and an indicator that your car requires some braking system maintenance.
Signs of warped rotors
Rotors are an important part of your car’s braking system, but how can you tell whether the rotors are warped or whether it is something else? Is it safe to drive on warped rotors?
Warped rotors generally come on over time so it may be difficult to immediately notice that there is a problem with the rotors. Noticeable changes in the braking system are a sign that there is something amiss.
A change such as a vibration through the brake pedal, or pulling or veering when the brakes are applied firmly at higher rates of speed may indicate that the rotors on your car may be warped. Along with a possible vibration felt through the brake pedal and system, you may feel a vibration in the steering wheel if your rotors are warped.
Due to the uneven pressure, thinning of materials and subsequent heat, warped rotors can cause uneven and unpredictable braking.
A visual check of your braking system can also show signs of warped rotors. To take a look yourself, you’ll need to ensure that the vehicle is parked with the steering wheel turned all the way to the left or to the right to allow you a better view of the braking area.
Take a look at the brake pads at the same time. If less than 1/4′ of brake pad is visible the rotors may need to be changed. Rotors cause unnatural wear on brake pads. As the rotors wear onto the brake pads, you may begin to notice grooves or scored marks in the metal of the rotor.
These marks, or scoring, also cause a thinning of the metal, which can compromise the safety of the rotors and, therefore, the braking reliability. Any signs of rotor scoring should prompt a visit to the nearest automotive repair shop.
The marking or scoring of metal is caused by the metal of the warped rotor being applied unevenly to the surface of the brake pad. This uneven application will generally cause a squeaking noise. Squeaking or squealing noises that occur when you apply the brake pedal could be a sign of warped rotors and should be investigated accordingly. Squeaking coming from the brake area is generally an indication that some type of brake system maintenance is needed.
Causes of warped rotors
Rotors are a working component of the braking system and wear down over time. As these parts wear down, rotors included, their reliability suffers. Wear in one system component can cause unintended stress on other parts, causing them to wear at a faster rate and different than expected.
Braking habits can also determine the likelihood of your rotors warping. Highway speeds coupled with frequent sharp stops, plus inexpensive rotors and brake pads is a relatively good recipe for warped rotors. While cost usually always plays a part, the replacement materials you use should be sufficient for the type of driving required of you.
Issues warped rotors cause
Warped rotors can cause a variety of issues with your braking system. As the disc becomes thinner it becomes hotter faster which can cause the entire braking system to overheat. Overheating can cause a variety of related and unrelated component failures if not addressed immediately.
While cost usually always plays a part, the replacement materials you use should be sufficient for the type of driving required of you.
Due to the uneven pressure, thinning of materials and subsequent heat, warped rotors can cause uneven and unpredictable braking. Within the braking system, brake fluid builds up because of the unintended motion and vibration of the brake pads.
This can lead to loss of hydraulic pressure within the braking system which can lead to the loss of brake control. Along with the possible loss of brake control is the potential effect of increased stopping time.
The risk of increased stopping time is greater if the warped rotor is located on the drive axle. If the warped rotors are causing vibrations and uneven braking, the risk of loss of traction in snow and rain also becomes greater.
Long-term effects of warped rotors
Drivers often don’t notice that their rotors are warped until it has caused an issue elsewhere. Driving for long periods of time with warped rotors most commonly causes stress on other mechanical components of the braking system such as calipers, bolts, ball joints and tie rod ends, but can also lead to Anti-lock Braking System sensor damage.
In the case of warped rotors, depending on the severity of the warp, you can have them machined or turned, which is essentially the rotor being sanded down, or you can replace them. Machined or turned rotors will be thinner, and you may have subsequent issues with the braking system overheating.
Machining or turning rotors should be considered a short-term solution. When you machine repair or replace your rotors, you should be sure to change the brake pads at the same time, as the pads will be worn unevenly due to the warped rotors.
A deeper dive — Related reading from the 101:
Read here for DIY car maintenance tips.
Looking to buy a new car? See whether you should buy or lease a new car.