Overview
- Brake rotor runout refers to the deviation of a brake rotor’s surface from a perfectly flat plane.
- When the brake rotor is out of balance, it can cause vibrations that are felt through the steering wheel or brake pedal.
- This device is attached to the brake rotor and measures the amount of deviation from a flat plane.
Understanding Brake Rotor Runout
Brake rotor runout refers to the deviation of a brake rotor’s surface from a perfectly flat plane. When a brake rotor exhibits runout, it can cause vibrations, pulsations, and even premature brake wear. In this comprehensive guide, we’ll delve into the causes, symptoms, and solutions related to brake rotor runout.
Causes of Brake Rotor Runout
- Warping: Excessive heat buildup during braking can cause the brake rotor to warp or bend.
- Uneven wear: If the brake pads are not evenly worn, they can create an uneven surface on the rotor.
- Manufacturing defects: Brake rotors can sometimes have manufacturing defects that cause runout.
- Improper installation: Incorrectly installed brake rotors can lead to misalignment and runout.
- Corrosion: Corrosion on the brake rotor’s surface can create unevenness and cause runout.
Symptoms of Brake Rotor Runout
- Vibration in the steering wheel or brake pedal: When the brake rotor is out of balance, it can cause vibrations that are felt through the steering wheel or brake pedal.
- Pulsation when braking: As the brake pads make contact with an uneven rotor, it can create a pulsating sensation when braking.
- Reduced braking performance: Runout can reduce the effectiveness of the brakes, leading to longer stopping distances.
- Noises: Brake rotor runout can produce squealing or grinding noises during braking.
Diagnosing Brake Rotor Runout
To diagnose brake rotor runout, a mechanic will typically use a dial indicator. This device is attached to the brake rotor and measures the amount of deviation from a flat plane. A runout of more than 0.002 inches is considered excessive.
Solutions for Brake Rotor Runout
- Resurfacing: If the runout is within certain limits, the brake rotor can be resurfaced to remove the uneven surface.
- Replacement: In cases of severe runout or if the rotor is damaged, it will need to be replaced.
- Proper installation: Ensure that the brake rotors are installed correctly to prevent runout.
- Regular maintenance: Inspect the brake system regularly and address any issues that may lead to runout.
Preventing Brake Rotor Runout
- Avoid excessive braking: Hard braking can generate excessive heat, which can warp the brake rotors.
- Use high-quality brake pads: Cheap brake pads can wear unevenly and cause runout.
- Have the brakes inspected regularly: Regular inspections can identify and address potential problems that could lead to runout.
Conclusion: Maintaining Optimal Brake Performance
Brake rotor runout can significantly impact the performance and safety of your vehicle. By understanding the causes, symptoms, and solutions related to brake rotor runout, you can ensure that your brakes are operating optimally. Regular maintenance and proper driving habits will help prevent runout and maintain the integrity of your braking system.
FAQ
Q: What is the acceptable amount of brake rotor runout?
A: Less than 0.002 inches.
Q: Can I drive with brake rotor runout?
A: Yes, but it can compromise braking performance and safety.
Q: Why do my brake rotors warp so quickly?
A: Excessive braking, low-quality brake pads, and improper installation can all contribute to rapid rotor warping.
Q: Can brake rotor runout cause vibrations in the steering wheel?
A: Yes, excessive runout can create vibrations that are felt through the steering wheel.
Q: How often should I have my brake rotors inspected?
A: At least once a year or every 12,000 miles.
