What happens if you don't bed-in brakes?

If you don't bed-in brakes, the brake pads will not properly transfer a uniform layer of friction material onto the rotors, leading to significantly compromised performance, noise, and potential safety issues.

The Importance of Bedding-In Brakes

Bedding-in, also known as break-in or burnishing, is a crucial process for new brake pads and rotors. It involves a series of controlled stops that gradually bring the brake components up to operating temperature. This process ensures that the brake pad material is evenly transferred onto the rotor surface, creating an optimal friction layer for consistent and effective braking. It also helps to "cure" the resins in the pad material, preventing glazing and ensuring the pads perform as designed.

Immediate Consequences of Not Bedding-In

Failing to properly bed-in your brakes can lead to several noticeable and detrimental effects:

Brake Judder: The Primary Issue

The most common and significant consequence of not bedding-in brakes is the development of "brake judder." This manifests as a vibration, which can sometimes be severe, felt through the steering wheel, brake pedal, and the vehicle's suspension.

• Uneven Film Buildup: Without proper bedding-in, the brake pads fail to deposit an even film of friction material onto the rotors. Instead, the material builds up unevenly across the rotor surface.
• Pads Losing and Regaining Contact: As the rotors rotate, the brake pads encounter these uneven deposits. This causes the pads to repeatedly lose and regain full contact with the discs, leading to the pulsating vibration known as judder.
• Rotor Runout: Over time, this uneven friction material can lead to actual thickness variations (DTV) in the rotor, making the problem worse and requiring more extensive repair.

Reduced Braking Performance

Initially, unbedded brakes will not perform at their peak.

• Lack of Initial Bite: The brakes may feel spongy or less responsive, lacking the immediate stopping power you expect.
• Increased Stopping Distances: Without the optimal friction layer, the braking efficiency is reduced, potentially leading to longer stopping distances, which compromises safety.
• Fading: The brakes might be more prone to "fade" under heavy or prolonged use, where their stopping power diminishes significantly due to overheating.

Increased Wear and Noise

Improper bedding can also lead to premature wear and undesirable sounds.

• Premature Wear: The uneven contact and friction can cause accelerated and uneven wear on both the brake pads and the rotors.
• Noise: You might experience excessive squealing, grinding, or groaning noises during braking as the pads struggle to make consistent contact with the rotors.

Long-Term Impacts

Neglecting the bedding-in process can lead to long-term issues that are costly and affect vehicle safety:

• Compromised Safety: Reduced braking performance and judder can make the vehicle unpredictable in emergency stopping situations.
• Costly Repairs: Persistent judder or severe uneven wear often necessitates resurfacing or replacing the rotors, along with new brake pads, much sooner than would typically be required.

Preventing Issues: The Bedding-In Process

While the exact procedure can vary slightly by manufacturer, the general process involves a series of moderate to firm stops from various speeds, allowing the brakes to cool between sets. This controlled heating and cooling cycles uniformly deposit the pad material and prepare the brakes for optimal performance.

What to Do If You Experience Judder

If you've failed to bed-in your brakes and are experiencing judder:

• Re-attempt Bedding-In: For minor judder, sometimes performing a proper bedding-in procedure can help clean up and even out the rotor surface.
• Inspection: Have a mechanic inspect the rotors for significant unevenness or runout.
• Resurfacing or Replacement: If the judder is severe or the rotors are physically warped or have significant thickness variations, they may need to be resurfaced (turned) or, more commonly, replaced entirely along with new pads.

Comparison: Bedded-In vs. Not Bedded-In Brakes