The frustration that comes with brake rotors that have become warped, grooved, or rusted is real. The solution? Resurfacing them. In addition to restoring your rotors to their former glory, resurfacing them can also save you the expense of buying new rotors. Here’s a step-by-step guide on how to resurface your brake rotors like a pro.
Before you begin, gather your tools and materials. You will need a brake rotor resurfacing machine, a wire brush, brake cleaner, and safety glasses. Once you have your tools and materials, you can begin the resurfacing process. First, remove the brake rotors from the vehicle. Then, clean the rotors with a wire brush and brake cleaner. Finally, place the rotors on the resurfacing machine and follow the manufacturer’s instructions. Once the rotors have been resurfaced, reinstall them on the vehicle and enjoy the smooth, quiet ride that comes with new rotors.
However, it is important to note that resurfacing brake rotors is not always the best solution. If the rotors are too thin or cracked, they should be replaced. Additionally, if the rotors have been resurfaced too many times, they may need to be replaced. If you are unsure whether or not your brake rotors need to be resurfaced, consult with a qualified mechanic. They can assess the condition of your rotors and make the best recommendation for your vehicle.
Assessing Rotor Damage
It’s crucial to thoroughly assess rotor damage before deciding whether resurfacing is necessary. Here are some key factors to consider:
Visual Inspection
- Deep Grooves and Cracks: Examine the rotors for any deep grooves or cracks that may indicate excessive wear or thermal distortion. These defects can compromise braking performance and should be replaced.
Thickness Variation
- Minimum Thickness: Check the rotor thickness using a micrometer or caliper. Rotors below the manufacturer’s specified minimum thickness must be replaced to ensure sufficient friction material contact.
- Runout: Inspect the rotors for any unevenness or "runout" in the surface. Excessive runout can cause vibrations and premature wear, necessitating resurfacing or replacement.
Surface Rust and Corrosion
- Surface Rust: Minor surface rust can often be removed during resurfacing, but deep corrosion or pitting may require rotor replacement.
- Corrosion on Mounting Surfaces: Check the rotor’s mounting surfaces for any corrosion or debris that could affect its proper fitment. Cleaning or resurfacing may be necessary before reinstallation.
Heat Dissipation
- Blueing or Discoloration: Excessive heat can cause the rotors to turn blue or discolor. This indicates overheating and may compromise rotor performance. Resurfacing can potentially restore the rotor’s heat dissipation capabilities.
Other Considerations
- Warped Rotors: Warped rotors can also cause vibrations and braking issues. However, in some cases, it may be possible to resurface slightly warped rotors to restore functionality.
- Wear Indicators: Some manufacturers include wear indicators on the rotors. When the indicators are no longer visible, it’s an indication that the rotors need to be replaced.
Safety Precautions for Resurfacing
Before starting the resurfacing process, it is crucial to prioritize safety by adhering to these essential precautions:
1. Park Safely
Park the vehicle on a stable and level surface. Engage the parking brake firmly to prevent any movement while working on the rotors.
2. Wear Protective Gear
Protect yourself from potential hazards by donning appropriate safety gear. This includes safety glasses to safeguard your eyes from flying debris, gloves to protect your hands from cuts and abrasions, and a dust mask to minimize inhalation of harmful particles created during resurfacing.
Additionally, ensure you have adequate ventilation in the work area to dissipate dust and fumes.
When using an electric grinder, ensure the power cord is in good condition and not frayed or damaged. Securely connect the grinder to a grounded power source. Keep the work area well-lit to enhance visibility and reduce the risk of accidents.
3. Inspect the Rotors
Before resurfacing, carefully inspect the rotors for excessive wear, cracks, or other damage. If any significant issues are detected, it is advisable to replace the rotors rather than resurfacing them.
4. Measure Rotor Thickness
Using a micrometer, meticulously measure the thickness of the rotors at multiple points. Compare the readings with the manufacturer’s specifications. If the rotors are excessively thin, resurfacing may not be feasible, and replacement may be necessary.
5. Use Proper Technique
When resurfacing rotors, it is crucial to employ proper technique to ensure an even surface and prevent excessive material removal. Hold the grinder securely and maintain a consistent angle throughout the process.
Preparing the Rotor for Resurfacing
1. Remove the Rotor from the Vehicle
* Park the vehicle on a level surface and engage the parking brake.
* Loosen the lug nuts on the wheel that corresponds to the rotor you want to resurface.
* Use a floor jack to lift the vehicle and place a jack stand under the frame for safety.
* Remove the wheel by loosening the lug nuts completely.
* Unbolt the rotor from the wheel hub using a socket wrench.
2. Clean the Rotor Surface
* Use a wire brush or sandpaper to remove any rust, dirt, or debris from the surface of the rotor.
* Wipe the rotor clean with a brake cleaner to remove any remaining particles.
* Inspect the rotor for any cracks, gouges, or other damage. If any damage is found, the rotor should be replaced rather than resurfaced.
3. Inspect the Rotor Thickness
* Measure the thickness of the rotor using a micrometer or calipers.
* Compare the measured thickness to the manufacturer’s minimum thickness specification for the rotor.
* If the rotor is below the minimum thickness, it should not be resurfaced and should be replaced instead.
Choosing the Right Abrasive Wheel
Selecting the appropriate abrasive wheel is crucial for effective rotor resurfacing. Here are the key factors to consider:
Type of Abrasive: There are two main types of abrasives: alumina and zirconia. Alumina is less expensive and more commonly used, while zirconia is more durable and provides a finer finish.
Grain Size: The grain size refers to the size of the abrasive particles. A coarser grain (e.g., 36-grit) removes material quickly but leaves a rougher surface. A finer grain (e.g., 60-grit or higher) produces a smoother finish but takes longer to remove material.
Bond Type: The bond type refers to the material that holds the abrasive particles together. A harder bond (e.g., ceramic) holds the particles more tightly, resulting in a longer-lasting wheel. A softer bond (e.g., resin) releases the particles more easily, making the wheel more forgiving.
Wheel Dimensions: The wheel should be sized appropriately for the rotor being resurfaced. The diameter and thickness of the wheel will determine its cutting depth and contact area.
The following table provides guidelines for selecting an abrasive wheel based on the type of rotor material and desired finish:
| Rotor Material | Abrasive Type | Grain Size | Bond Type |
|---|---|---|---|
| Cast Iron | Alumina | 36-60 grit | Hard (ceramic) |
| Steel | Zirconia | 40-80 grit | Medium (resin) |
| Aluminum | Alumina | 60-120 grit | Soft (resin) |
Setting the Proper Grinding Depth
Determining the proper grinding depth is crucial to ensure effective resurfacing and avoid damaging the rotors. Here’s a detailed guide to help you accurately set the grinding depth:
1. Measure the Rotor Thickness
Using a micrometer, measure the thickness of the rotor at several points along its surface. Record the minimum thickness measurement.
2. Determine the Required Grinding Depth
Refer to the vehicle manufacturer’s specifications for the minimum allowable rotor thickness. Subtract the measured minimum thickness from the specified minimum thickness to determine the required grinding depth.
3. Set the Grinding Depth on the Lathe
Locate the grinding depth adjustment knob or wheel on the brake lathe. Turn the knob or wheel until the grinding depth indicator matches the required grinding depth.
4. Test the Grinding Depth
Grind a small area of the rotor (approximately 1 inch) at the determined grinding depth. Measure the thickness of the ground area to verify that it matches the intended depth.
5. Adjust the Grinding Depth as Needed
If the measured thickness does not match the desired depth, make small adjustments to the grinding depth knob or wheel. Re-grind a new area and measure the thickness again until the correct depth is achieved.
| Step | Action |
|---|---|
| 1 | Measure rotor thickness |
| 2 | Determine required grinding depth |
| 3 | Set grinding depth on lathe |
| 4 | Test grinding depth |
| 5 | Adjust grinding depth as needed |
Grinding the Rotor Surface
Preparation
Before grinding, ensure the rotor is secure on a resurfacing machine. Clean the rotor surface thoroughly using a brake cleaning agent to remove any dirt, grease, or debris.
Rotor Cutting Depth
Determine the recommended cutting depth for your specific rotor. This information can typically be found on the rotor itself or in the vehicle’s service manual. The cutting depth is usually between 0.010 to 0.020 inch.
Grinding Pattern
Use a coarse grinding wheel to remove the damaged surface material. Gradually switch to finer grinding wheels to smooth the surface. Grind in a circular motion, starting from the outside edge and moving towards the center.
Alignment
Ensure the grinding head is parallel to the rotor surface. Misalignment can cause uneven cutting and damage to the rotor.
Cutting Tool Pressure
Apply moderate pressure on the grinding head. Excessive pressure can damage the rotor, while insufficient pressure will not remove enough material. Adjust the pressure as necessary to achieve a smooth, uniform surface.
Frequency of Grinding
The frequency of grinding depends on the condition of the rotor. If the rotor is badly warped or damaged, multiple grinding sessions may be necessary. Grind the rotor until the damaged surface is completely removed and the rotor is flat and smooth.
Table: Grinding Parameters for Different Rotor Types
| Rotor Type | Cutting Depth (inch) | Grinding Speed (RPM) |
|---|---|---|
| Solid Cast Iron | 0.010-0.015 | 60-80 |
| Vented Cast Iron | 0.015-0.020 | 80-100 |
| Steel | 0.010-0.015 | 120-150 |
Deburring and Cleaning the Rotor
After removing any rust or corrosion from the rotor’s surface, you can begin deburring and cleaning it. Deburring involves removing any sharp edges or burrs that may have formed during the resurfacing process. Use a deburring tool or a fine-grit sandpaper to smooth out any rough edges. Cleaning the rotor is essential to remove any remaining debris or contaminants that could affect its performance. Use a brake cleaner and a clean rag to thoroughly clean the rotor’s surface, ensuring it is free of any dirt, grease, or oil.
Deburring the Rotor’s Surface
Deburring the rotor’s surface involves removing any sharp edges or burrs that may have formed during the resurfacing process. These burrs can cause premature wear on the brake pads and can also lead to a decrease in braking performance. To deburr the rotor, use a deburring tool or a fine-grit sandpaper. Start by lightly sanding the edges of the rotor, taking care not to remove too much material. Once the burrs have been removed, wipe down the rotor with a clean rag to remove any remaining debris.
Cleaning the Rotor
Once the rotor has been deburred, it is important to clean it thoroughly to remove any remaining debris or contaminants. This will help to ensure that the rotor performs at its best. To clean the rotor, use a brake cleaner and a clean rag. Spray the brake cleaner onto the rotor and then wipe it down with the rag. Repeat this process until the rotor is free of any dirt, grease, or oil.
| Tools Needed for Deburring and Cleaning |
|---|
| Deburring tool or fine-grit sandpaper |
| Brake cleaner |
| Clean rag |
Verifying Rotor Thickness and Runout
Measuring Rotor Thickness
Before resurfacing the rotors, it’s crucial to verify their thickness to ensure they meet the manufacturer’s specifications. This is done using a micrometer or a dedicated rotor measuring tool. Measure the thickness of the rotor in several locations, including the outer, inner, and middle portions. The thickness should be within the acceptable range specified by the vehicle’s service manual.
Runout Testing
Runout refers to the variation in the rotor surface as it spins. Excessive runout can cause vibrations and reduce braking performance. To test for runout, use a dial indicator mounted on a magnetic base. Position the indicator tip against the rotor surface and rotate the rotor slowly by hand. Observe the dial indicator’s needle; an acceptable runout value is typically between 0.002″ to 0.005″.
Table: Acceptable Rotor Thickness and Runout Values
| Vehicle Model | Rotor Thickness | Runout |
|---|---|---|
| Toyota Camry | 24.0 mm | 0.003″ |
| Ford F-150 | 30.0 mm | 0.004″ |
| Honda Civic | 22.0 mm | 0.002″ |
Reinstalling the Resurfaced Rotor
Once the rotors have been resurfaced, it’s time to reinstall them. This process is relatively simple, but it’s important to follow the steps carefully to ensure that the rotors are installed correctly.
Step 1: Clean the Rotor Hub and Caliper Mounting Surface
Before installing the rotor, it’s important to clean the rotor hub and the caliper mounting surface. This will help to ensure that the rotor is properly seated and that there is no debris that could cause vibration or noise.
Step 2: Apply Anti-Seize to the Rotor Hub
To prevent the rotor from seizing to the hub, it’s important to apply a small amount of anti-seize to the hub before installing the rotor.
Step 3: Install the Rotor
Once the rotor hub has been cleaned and anti-seize has been applied, the rotor can be installed. Carefully align the rotor with the hub and slide it into place.
Step 4: Tighten the Rotor Bolts
Once the rotor is in place, it’s important to tighten the rotor bolts to the specified torque. This will help to ensure that the rotor is properly secured.
Step 5: Install the Caliper
Once the rotor has been tightened, the caliper can be installed. Carefully align the caliper with the rotor and slide it into place.
Step 6: Tighten the Caliper Bolts
Once the caliper is in place, it’s important to tighten the caliper bolts to the specified torque. This will help to ensure that the caliper is properly secured.
Step 7: Bleed the Brakes
Once the caliper has been tightened, it’s important to bleed the brakes. This will help to remove any air from the brake system and ensure that the brakes are working properly.
Step 8: Test the Brakes
Once the brakes have been bled, it’s important to test the brakes to make sure that they are working properly. This can be done by driving the vehicle and applying the brakes. The brakes should feel firm and responsive.
Step 9: Inspect the Rotors and Pads Regularly
It’s important to inspect the rotors and pads regularly to ensure that they are in good condition. The rotors should be smooth and free of cracks or gouges. The pads should be at least 1/4 inch thick. If the rotors or pads are worn, they should be replaced.
| Step | Action | Torque |
|---|---|---|
| 1 | Clean the rotor hub and caliper mounting surface | N/A |
| 2 | Apply anti-seize to the rotor hub | N/A |
| 3 | Install the rotor | N/A |
| 4 | Tighten the rotor bolts | 100 ft-lbs |
| 5 | Install the caliper | N/A |
| 6 | Tighten the caliper bolts | 150 ft-lbs |
| 7 | Bleed the brakes | N/A |
| 8 | Test the brakes | N/A |
| 9 | Inspect the rotors and pads regularly | N/A |
Avoiding Common Mistakes in Resurfacing
1. Skipping the Preparation Step:
Thoroughly cleaning and inspecting the rotors before resurfacing removes debris, dirt, and rust, ensuring an optimal resurfacing result.
2. Using the Wrong Resurfacing Tool:
Various resurfacing tools exist, each suited to specific rotor types. Using an inappropriate tool can damage the rotors or produce uneven surfaces.
3. Applying Too Much Force:
Excessive force during resurfacing can warp or groove the rotors, leading to vibration and brake performance issues.
4. Not Following Manufacturer’s Instructions:
Ignoring manufacturer guidelines for speed, depth, and coolant usage can compromise the resurfacing outcome.
5. Failing to Check Rotor Thickness:
Resurfacing too frequently can reduce the rotor’s thickness below its minimum specification, potentially compromising safety.
6. Not Cleaning the Debris After Resurfacing:
Metal shavings and dust generated during resurfacing can impair braking efficiency if not thoroughly cleaned afterward.
7. Overtightening Caliper Bolts:
Excessive torque on caliper bolts can damage the rotors or caliper housing, leading to uneven brake pressure.
8. Not Bleeding the Brake System:
Air trapped in the brake lines after resurfacing can result in spongy or ineffective brakes.
9. Driving Immediately After Resurfacing:
Newly resurfaced rotors require a break-in period to establish a proper contact surface. Driving heavily immediately after resurfacing can glaze the rotors.
10. Ignoring Other Brake Components:
Resurfacing alone may not resolve all brake issues. Inspecting and replacing other components such as brake pads, calipers, and brake lines ensures optimal braking performance.
| Mistake | Consequence |
|---|---|
| Skipping preparation | Debris and dirt can contaminate the resurfacing |
| Using the wrong tool | Damage to rotors or uneven surfaces |
| Applying too much force | Warped or grooved rotors, vibration, and poor braking |
How to Resurface Rotors
Resurfacing rotors is a process that involves removing a thin layer of material from the surface of the rotor, which can help to smooth out any unevenness or imperfections. This can help to improve braking performance and reduce noise. Rotors can be resurfaced using a lathe or a grinder, and the process typically takes about 30 minutes to 1 hour per rotor.
If you are experiencing any of the following problems, you may need to resurface your rotors:
- Squealing or grinding noises when braking
- Vibrations when braking
- Uneven braking
- Reduced braking performance
If you are not comfortable resurfacing rotors yourself, you can take your vehicle to a mechanic to have it done. The cost of resurfacing rotors typically ranges from $50 to $150 per rotor.
People Also Ask
Can I resurface rotors myself?
Yes, you can resurface rotors yourself using a lathe or a grinder. However, it is important to follow the manufacturer’s instructions carefully to avoid damaging the rotors.
How often should I resurface my rotors?
The frequency with which you need to resurface your rotors will depend on your driving habits and the condition of your brakes. If you drive in a lot of stop-and-go traffic or if you do a lot of hard braking, you may need to resurface your rotors more often. However, most people only need to resurface their rotors every few years.
How much does it cost to resurface rotors?
The cost of resurfacing rotors typically ranges from $50 to $150 per rotor. The cost will vary depending on the type of rotor and the shop that you take your vehicle to.
