Converting to disc brakes is a significant upgrade for many vehicles, offering improved stopping power, better performance in wet conditions, and enhanced overall safety. While drum brakes served their purpose for many years, disc brakes provide superior heat dissipation and a more consistent braking feel. This guide will walk you through the process, considerations, and components needed for a successful disc brake conversion.
Disc Brake Conversion: A Comprehensive Guide
| Topic | Description | Considerations |
|---|---|---|
| Why Convert to Disc Brakes? | Advantages of disc brakes over drum brakes. | Improved stopping power, better performance in wet conditions, reduced brake fade, ease of maintenance. |
| Front vs. Rear Conversion | Deciding whether to convert front, rear, or both axles. | Front conversions offer the most significant improvement in stopping power. Rear conversions can improve balance and reduce rear-end lockup. Consider your vehicle's intended use and budget. |
| Required Components | List of necessary parts for a disc brake conversion kit. | Rotors, calipers, brake pads, caliper brackets, brake lines, master cylinder (potentially), proportioning valve (potentially), backing plates (sometimes), and potentially a new emergency brake system. |
| Choosing a Conversion Kit | Factors to consider when selecting a disc brake conversion kit. | Vehicle make and model, axle type, wheel size, desired braking performance, budget, and kit completeness. Read reviews and compare components from different manufacturers. |
| Master Cylinder Upgrade | Determining if a master cylinder upgrade is necessary. | Brake pedal feel, braking performance, and the master cylinder's ability to provide sufficient fluid volume and pressure for the new calipers. Larger calipers typically require a master cylinder with a larger bore. |
| Proportioning Valve Adjustment/Replacement | Understanding the role of the proportioning valve and how to adjust or replace it. | Prevents rear wheel lockup by reducing pressure to the rear brakes. May need adjustment or replacement to match the new front-to-rear braking balance. |
| Brake Lines and Hoses | Selecting and installing appropriate brake lines and hoses. | DOT-approved lines are essential. Stainless steel braided lines provide better performance and durability. Ensure proper length and routing. |
| Emergency Brake System | Addressing the emergency brake system after the conversion. | Many drum brake systems use the rear drums for the emergency brake. Conversion kits often include a separate emergency brake system that integrates with the new rear calipers or retains the original system with modifications. |
| Installation Process (Overview) | General steps involved in a disc brake conversion. | Removal of existing drum brakes, installation of caliper brackets, rotors, calipers, brake pads, brake lines, and bleeding the brake system. |
| Bleeding the Brakes | Proper bleeding techniques to ensure optimal braking performance. | Use a pressure bleeder, vacuum bleeder, or the traditional two-person method. Bleed in the correct sequence (farthest from the master cylinder first). |
| Wheel Fitment | Ensuring that your wheels are compatible with the new disc brakes. | Check the wheel's offset and inner diameter to ensure it clears the calipers and rotors. Spacers may be needed in some cases. |
| Cost Considerations | Estimating the overall cost of a disc brake conversion. | Cost of the conversion kit, master cylinder (if needed), proportioning valve (if needed), brake lines, tools, and professional installation (if applicable). |
| Safety Precautions | Important safety measures to take during the conversion process. | Wear safety glasses, use jack stands, disconnect the battery, and properly dispose of brake fluid. |
| Troubleshooting Common Issues | Addressing common problems that may arise during or after the conversion. | Brake pedal feel, brake noise, brake drag, and fluid leaks. |
| Tools Required | List of essential tools for a disc brake conversion. | Wrenches, sockets, screwdrivers, pliers, brake line wrench, torque wrench, jack stands, jack, brake fluid bleeder, and potentially a brake line flaring tool. |
| Long-Term Maintenance | Routine maintenance tasks to keep your disc brakes in good condition. | Regular inspection of brake pads, rotors, calipers, and brake lines. Replacing worn components promptly. Flushing the brake fluid every 2-3 years. |
| Legal Considerations | Understanding any legal requirements related to brake modifications. | Check local regulations regarding brake modifications and inspections. Ensure that the conversion meets all applicable safety standards. |
| Performance Expectations | What to expect in terms of braking performance after the conversion. | Improved stopping distances, better braking feel, and reduced brake fade. The exact improvement will depend on the vehicle, components used, and driving conditions. |
Detailed Explanations
Why Convert to Disc Brakes?
Disc brakes offer significant advantages over drum brakes. They provide superior stopping power due to increased friction surface area and better heat dissipation. This improved heat management leads to reduced brake fade, especially under heavy braking or repeated stops. Disc brakes also perform better in wet conditions, as they self-clean more effectively than drum brakes. Finally, disc brakes are generally easier to maintain due to their simpler design and more accessible components.
Front vs. Rear Conversion
Deciding whether to convert the front, rear, or both axles depends on your vehicle's needs and budget. Front conversions offer the most noticeable improvement in stopping power, as the front brakes typically handle a larger percentage of the braking load. Rear conversions can improve overall braking balance and reduce the risk of rear-end lockup, particularly in light vehicles. Converting both axles provides the most comprehensive upgrade, but it is also the most expensive and complex. Consider your vehicle's intended use (e.g., daily driving, towing, racing) and budget when making this decision.
Required Components
A complete disc brake conversion kit typically includes the following components:
- Rotors: The rotating discs that the brake pads clamp onto.
- Calipers: The hydraulic components that house the brake pads and apply pressure to the rotors.
- Brake Pads: The friction material that contacts the rotors to slow the vehicle.
- Caliper Brackets: Mount the calipers to the vehicle's suspension.
- Brake Lines: Hoses that carry brake fluid from the master cylinder to the calipers.
- Master Cylinder (Potentially): The hydraulic pump that provides brake fluid pressure. May need upgrading for increased volume.
- Proportioning Valve (Potentially): Regulates brake pressure to the rear wheels to prevent lockup.
- Backing Plates (Sometimes): Protect the rotors from debris.
- Emergency Brake System: A mechanism to apply the brakes in an emergency or when parking.
Choosing a Conversion Kit
When selecting a disc brake conversion kit, consider the following factors:
- Vehicle Make and Model: Ensure the kit is specifically designed for your vehicle.
- Axle Type: Different axles require different mounting brackets and components.
- Wheel Size: The rotors and calipers must fit inside your wheels.
- Desired Braking Performance: Choose a kit that meets your performance requirements (e.g., daily driving, towing, racing).
- Budget: Disc brake conversion kits vary in price.
- Kit Completeness: Some kits include all necessary components, while others may require additional purchases.
- Reviews: Research the kit and read reviews from other users.
Master Cylinder Upgrade
The master cylinder is a critical component of the braking system. If the existing master cylinder is not capable of providing sufficient fluid volume and pressure to the new calipers, a master cylinder upgrade will be required. Signs that an upgrade is needed include a soft or spongy brake pedal feel and reduced braking performance. Generally, larger calipers require a master cylinder with a larger bore size.
Proportioning Valve Adjustment/Replacement
The proportioning valve regulates brake pressure to the rear wheels to prevent premature lockup. After a disc brake conversion, the front-to-rear braking balance may change, requiring adjustment or replacement of the proportioning valve. An adjustable proportioning valve allows you to fine-tune the braking balance.
Brake Lines and Hoses
Use DOT-approved brake lines and hoses for safety and reliability. Stainless steel braided brake lines offer improved performance and durability compared to rubber lines. Ensure the brake lines are the correct length and properly routed to avoid chafing or kinking.
Emergency Brake System
Many drum brake systems utilize the rear drums for the emergency brake. After a disc brake conversion, you will need to address the emergency brake system. Some conversion kits include a separate emergency brake system that integrates with the new rear calipers. Others retain the original system with modifications. Proper functionality of the emergency brake is crucial for safety.
Installation Process (Overview)
The disc brake conversion process typically involves the following steps:
- Removal of Existing Drum Brakes: Disconnect the brake lines and remove the drum brake components.
- Installation of Caliper Brackets: Bolt the caliper brackets to the vehicle's suspension.
- Installation of Rotors: Mount the rotors onto the hubs.
- Installation of Calipers: Attach the calipers to the caliper brackets.
- Installation of Brake Pads: Insert the brake pads into the calipers.
- Installation of Brake Lines: Connect the brake lines to the calipers and master cylinder.
- Bleeding the Brake System: Remove air from the brake lines.
Bleeding the Brakes
Proper bleeding is essential for optimal braking performance. Air in the brake lines can cause a spongy brake pedal and reduced stopping power. Use a pressure bleeder, vacuum bleeder, or the traditional two-person method. Bleed the brakes in the correct sequence, starting with the wheel furthest from the master cylinder and working your way closer.
Wheel Fitment
Ensure that your wheels are compatible with the new disc brakes. Check the wheel's offset and inner diameter to ensure it clears the calipers and rotors. Wheel spacers may be needed in some cases.
Cost Considerations
The cost of a disc brake conversion can vary depending on the vehicle, components used, and whether you hire a professional installer. Factors to consider include the cost of the conversion kit, master cylinder (if needed), proportioning valve (if needed), brake lines, tools, and labor.
Safety Precautions
Safety is paramount during a disc brake conversion. Always wear safety glasses, use jack stands to support the vehicle, disconnect the battery, and properly dispose of brake fluid.
Troubleshooting Common Issues
Common problems that may arise during or after the conversion include:
- Spongy Brake Pedal: Air in the brake lines.
- Brake Noise: Improperly installed brake pads or worn rotors.
- Brake Drag: Calipers not releasing properly.
- Fluid Leaks: Loose brake line connections or damaged components.
Tools Required
Essential tools for a disc brake conversion include:
- Wrenches
- Sockets
- Screwdrivers
- Pliers
- Brake Line Wrench
- Torque Wrench
- Jack Stands
- Jack
- Brake Fluid Bleeder
- Brake Line Flaring Tool (potentially)
Long-Term Maintenance
To keep your disc brakes in good condition, perform regular maintenance tasks such as:
- Inspecting Brake Pads: Replace worn pads promptly.
- Inspecting Rotors: Check for wear and damage.
- Inspecting Calipers: Look for leaks or signs of damage.
- Inspecting Brake Lines: Check for cracks or leaks.
- Flushing Brake Fluid: Replace the brake fluid every 2-3 years.
Legal Considerations
Check local regulations regarding brake modifications and inspections. Ensure that the conversion meets all applicable safety standards.
Performance Expectations
After a successful disc brake conversion, you can expect:
- Improved Stopping Distances
- Better Braking Feel
- Reduced Brake Fade
Frequently Asked Questions
Why should I convert to disc brakes? Disc brakes offer superior stopping power, better performance in wet conditions, and reduced brake fade compared to drum brakes. They also tend to be easier to maintain.
Do I need to upgrade my master cylinder when converting to disc brakes? It depends on the size of the new calipers. Larger calipers typically require a master cylinder with a larger bore to provide sufficient fluid volume and pressure.
What is a proportioning valve, and do I need to adjust it after a conversion? A proportioning valve regulates brake pressure to the rear wheels to prevent lockup. It may need adjustment or replacement after a disc brake conversion to maintain proper braking balance.
Are stainless steel brake lines worth the extra cost? Yes, stainless steel braided brake lines offer improved performance and durability compared to rubber lines. They resist expansion under pressure, providing a firmer brake pedal feel.
How often should I bleed my brakes after a disc brake conversion? Bleed your brakes immediately after the conversion and then periodically (every 1-2 years) as part of regular maintenance.
Conclusion
Converting to disc brakes is a worthwhile upgrade that can significantly improve your vehicle's safety and performance. By carefully planning the conversion, selecting the right components, and following proper installation procedures, you can enjoy the benefits of enhanced braking for years to come. Remember to prioritize safety throughout the process and consult with a qualified mechanic if you have any doubts.