14/01/2016
The question of whether you should bed in brake pads is a common one among car enthusiasts and everyday drivers alike. While some might consider it an unnecessary step, the truth is that proper brake pad bedding-in, also known as burnishing, is a crucial process that significantly impacts the performance, lifespan, and quiet operation of your braking system. Ignoring this step can lead to suboptimal braking, premature wear, and annoying noises. This guide will delve into why bedding-in is so important and provide you with a clear, step-by-step process to ensure your new brake pads are performing at their absolute best.
What Exactly is Brake Pad Bedding-In?
Brake pad bedding-in is a process designed to create a uniform transfer layer of friction material from the brake pad onto the surface of the brake disc (rotor). This layer is essential for achieving the full braking potential of the pad and disc combination. During the manufacturing process, both the pads and the discs are very smooth and have microscopic imperfections. Bedding-in helps to mate these surfaces together, creating an even contact patch and ensuring that the friction material is applied consistently across the entire braking surface. This process also helps to cure the resins within the brake pad material, bringing them to their optimal operating temperature and hardness.
Why is Bedding-In So Important?
There are several compelling reasons why taking the time to bed in your new brake pads is vital:
- Optimal Stopping Power: An improperly bedded-in set of pads will not be able to generate the maximum friction coefficient. This means your car won't stop as quickly or as effectively as it should, which can be a serious safety concern. A well-bedded pad ensures a consistent and strong grip on the rotor.
- Reduced Noise and Vibration: The bedding-in process helps to smooth out any unevenness on the pad and rotor surfaces. This can significantly reduce or eliminate common braking issues like squealing, groaning, and juddering, leading to a more comfortable and refined driving experience.
- Extended Pad and Rotor Lifespan: When you don't bed in your brakes, you can cause uneven wear patterns. This can lead to premature wear of both the pads and the rotors, meaning you'll have to replace them sooner. A proper bedding-in procedure ensures that the wear is distributed evenly, maximizing the life of your components.
- Prevention of Glazing: Glazing occurs when the brake pad material overheats and hardens into a glassy, smooth surface. This dramatically reduces friction. Bedding-in, when done correctly, brings the pads up to temperature gradually, preventing this overheating and glazing.
- Consistent Performance: Bedding-in ensures that the brakes perform consistently across a wide range of temperatures and conditions. Whether you're driving in the city or tackling a winding country road, your brakes will be ready to perform.
When Should You Bed In Brake Pads?
You should always bed in new brake pads whenever they are replaced, whether you are fitting performance pads or standard replacements. This also applies if you are replacing your brake discs (rotors) or if you have had your existing discs machined. Essentially, any time the friction surfaces are new or resurfaced, bedding-in is a necessary step.
The Correct Brake Pad Bedding-In Procedure
There are various methods for bedding in brake pads, but the most common and effective approach involves a series of controlled stops. It's crucial to follow these steps carefully to achieve the desired results. The general principle is to apply moderate braking force to transfer a small amount of pad material to the rotor, without coming to a complete, prolonged stop, which can cause uneven deposits.
Step-by-Step Guide:
- Prepare the Vehicle: Ensure your vehicle is in a safe location, preferably a quiet road with minimal traffic, allowing for acceleration and deceleration. Make sure your new brake pads and any associated hardware (like shims) are correctly installed.
- Initial Light Stops (5-10 stops): Begin with gentle stops from a moderate speed (e.g., 30-40 mph or 50-65 km/h). Apply the brakes lightly, just enough to slow the vehicle down. Do not come to a complete halt. As you slow, release the brake pedal before the vehicle stops completely. Allow the vehicle to roll to a stop. Repeat this 5-10 times.
- Moderate Stops (5-8 stops): Increase your speed slightly (e.g., 40-50 mph or 65-80 km/h). Apply a firmer, but not emergency, brake pressure. Again, aim to slow the vehicle down significantly without bringing it to a complete stop. Release the brakes as you approach your stopping point and allow the car to roll. Repeat this 5-8 times.
- Harder Stops (2-3 stops): For the final phase, find a safe stretch of road where you can accelerate to a higher speed (e.g., 50-60 mph or 80-100 km/h). Apply firm, progressive braking, simulating a hard stop, but avoid locking up the wheels or engaging ABS if possible. Again, do not come to a complete stop. Release the brakes as you slow down and allow the car to roll. Repeat this 2-3 times.
- Cooling Down Period: After the final hard stop, drive for several minutes without using the brakes, allowing them to cool down. This is a critical step to prevent warping or glazing. Avoid heavy braking during this period. If you have to brake, do so gently.
Important Considerations During Bedding-In:
- Avoid Complete Stops: The most critical rule is not to stop the vehicle completely during the bedding-in process. Coming to a full stop can cause an uneven build-up of friction material on the rotor, leading to hot spots and potential issues.
- Don't Overheat: While you need to apply some heat to the pads and rotors, avoid excessively long or aggressive braking that could lead to severe overheating. The goal is a gradual, controlled transfer of material.
- Listen and Feel: Pay attention to any unusual noises or vibrations. If you experience significant issues, it might indicate a problem with the installation or the components themselves.
- Allow for Cooling: The cool-down drive is vital. It allows the heat to dissipate evenly and prevents thermal shock.
Comparison of Brake Pad Types and Bedding-In Needs
Different types of brake pads have varying bedding-in requirements. While the general principle remains the same, the intensity and duration might differ.
| Brake Pad Type | Bedding-In Intensity | Bedding-In Duration | Notes |
|---|---|---|---|
| Organic (Standard) | Light to Moderate | 5-10 stops | Generally less critical but still recommended for optimal performance and noise reduction. |
| Semi-Metallic | Moderate to Firm | 8-12 stops | Benefit significantly from a thorough bedding-in process for consistent stopping power and reduced noise. |
| Ceramic | Moderate to Firm | 10-15 stops | Require a thorough bedding-in to activate their full friction potential and prevent glazing. |
| High-Performance/Track Pads | Firm to Aggressive | 15-20 stops or manufacturer specific | Often require more aggressive bedding-in, sometimes with manufacturer-specific instructions, to handle extreme temperatures. It's crucial to follow the manufacturer's guide precisely. |
Frequently Asked Questions (FAQs)
Q1: How long does it take to bed in new brake pads?
The entire process, including the driving and cool-down period, typically takes about 15-30 minutes of driving, depending on traffic conditions and the number of stops required.
Q2: Can I bed in my brakes in a car wash?
No, a car wash is not a suitable place to bed in your brakes. You need a safe environment where you can accelerate and decelerate without causing a hazard.
Q3: What happens if I don't bed in my new brake pads?
If you don't bed in your new brake pads, you may experience reduced stopping power, increased braking noise, premature wear, and potential brake judder or glazing.
Q4: My new brakes are still noisy after bedding them in. What should I do?
While bedding-in reduces noise, some brake pad compounds are inherently noisier than others. If the noise is excessive or accompanied by vibration, it's advisable to have your brakes inspected by a qualified mechanic.
Q5: Can I use my new brakes immediately after bedding them in?
Yes, once the bedding-in process and cool-down period are complete, your brakes are ready for normal use. However, it's still a good idea to drive gently for the first few miles just to be sure.
Conclusion
In conclusion, the importance of bedding in your new brake pads cannot be overstated. It's a simple yet vital procedure that ensures your braking system performs at its peak, providing you with the stopping power, safety, and longevity you expect. By following the correct steps and understanding the principles behind this process, you can significantly enhance your driving experience and the lifespan of your brake components. So, the next time you replace your brake pads, remember to dedicate the time to bed them in properly – your safety and your car will thank you for it.
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