Key points
- Before beginning any work on your vehicle, ensure it is parked on a level surface, the parking brake is engaged, and the wheels are chocked.
- This can be done by resurfacing the rotor using a brake lathe or by replacing the rotor if it is excessively worn or warped.
- Once the rotor parallelism is corrected, reinstall the wheel and tighten the lug nuts to the specified torque using a torque wrench.
Maintaining brake rotor parallelism is crucial for ensuring optimal braking performance and preventing premature wear. Parallel rotors ensure even contact between the pads and rotors, resulting in consistent braking force and reduced judder. However, over time, rotors can become misaligned due to factors such as uneven wear, improper installation, or impact. Checking and correcting brake rotor parallelism is a relatively simple but essential task that can be performed using a few basic tools.
Tools Required
- Dial indicator with magnetic base
- Feeler gauge
- Brake cleaner
- Torque wrench
- Socket set
Step-by-Step Guide to Checking Brake Rotor Parallelism
1. Safety Precautions
Before beginning any work on your vehicle, ensure it is parked on a level surface, the parking brake is engaged, and the wheels are chocked.
2. Remove the Wheels
Using a socket wrench, loosen the lug nuts on the wheel you want to check. Lift the vehicle using a jack and remove the lug nuts completely. Carefully remove the wheel and set it aside.
3. Clean the Rotor Surface
Thoroughly clean the brake rotor surface using brake cleaner to remove any dirt, grease, or debris. This will ensure accurate readings.
4. Mount the Dial Indicator
Attach the magnetic base of the dial indicator to the caliper bracket or suspension component. Position the dial indicator tip on the rotor surface, ensuring it is parallel to the rotor’s axis of rotation.
5. Zero the Dial Indicator
Gently rotate the rotor by hand and zero the dial indicator to eliminate any initial offset.
6. Check Rotor Parallelism
Slowly rotate the rotor again and observe the dial indicator reading. The rotor is parallel if the dial indicator reading remains within 0.005 inches (0.127 mm) throughout the rotation. If the reading exceeds this value, the rotor is not parallel.
7. Measure Runout
If the rotor is not parallel, measure the runout using a feeler gauge. Insert the feeler gauge between the rotor surface and the dial indicator tip. The runout is the difference in the feeler gauge thickness at the highest and lowest points.
8. Correct Rotor Parallelism
If the rotor runout exceeds 0.005 inches (0.127 mm), it must be corrected. This can be done by resurfacing the rotor using a brake lathe or by replacing the rotor if it is excessively worn or warped.
9. Reinstall the Wheel
Once the rotor parallelism is corrected, reinstall the wheel and tighten the lug nuts to the specified torque using a torque wrench.
Signs of Misaligned Brake Rotors
- Uneven brake pad wear
- Brake judder or vibration
- Reduced braking performance
- Squealing or grinding noises while braking
Importance of Brake Rotor Parallelism
Parallel brake rotors are essential for:
- Consistent braking force
- Reduced brake judder
- Extended brake pad life
- Improved overall braking performance
Tips for Maintaining Brake Rotor Parallelism
- Regularly check and correct brake rotor parallelism as part of your vehicle maintenance schedule.
- Avoid aggressive braking or excessive heat buildup in the brakes.
- Use high-quality brake pads and rotors.
- Have your brakes inspected by a qualified mechanic if you experience any symptoms of misaligned rotors.
What People Want to Know
Q: How often should I check brake rotor parallelism?
A: It is recommended to check brake rotor parallelism every 10,000-15,000 miles or as needed if you experience any symptoms of misaligned rotors.
Q: Can I check brake rotor parallelism at home?
A: Yes, you can check brake rotor parallelism at home using the tools described in this guide. However, it is important to follow the steps carefully and ensure you are comfortable working on your vehicle.
Q: What are the consequences of neglecting brake rotor parallelism?
A: Neglecting brake rotor parallelism can lead to uneven brake pad wear, brake judder, reduced braking performance, and potentially more expensive repairs in the long run.
