How to Bed-in Your Brakes

by Dave Zeckhausen

Bedding allows your brakes to reach their full potential.  Until they are bedded, your brakes simply do not work as well as they can.  If you've installed a big brake kit, changed your pads and rotors, or even purchased a brand new car, you should set aside time to bed the brakes according to the instructions below.  Proper bedding improves pedal feel, reduces or eliminates brake squeal, prevents (and often cures) brake judder, reduces brake dust, and extends the life of your pads and rotors.  For more details on the theory of bedding, please refer to this article by Centric Parts: Pad and Rotor Bed-In Theory, Definitions and Procedures

Caution: Immediately after installing new pads, rotors or a big brake kit, the first few applications of the brakes will result in very little braking power.  Gently use the brakes a few times at low speed in order to build up some grip before blasting down the road at high speed.  Otherwise, you may be in for a nasty surprise the first time you hit the brakes at 60 mph.

If you have just installed rotors with zinc or cadmium plating, or if the rotors have an anti-corrosion phosphate coating, you should postpone the bedding process until normal driving has allowed your brake pads to polish the rotors clean and removed all traces of the plating or coating.  If your new brake rotors have an oily anti-corrosion coating, you should clean this off thoroughly with brake cleaning spray and/or hot soapy water.

Read and understand these bedding instructions completely before starting.  If you have questions, give us a call or email.  Do not substitute higher speeds for the 60mph called for in these instructions.  The heat in your brakes goes up exponentially as you increase the speed from which you brake.  If you make repeated stops from 80 or 90mph with street pads, you will overheat the brakes and may end up having to replace pads and/or rotors.

When following these instructions, avoid other vehicles.  Bedding is often best done early in the morning, when traffic is light, since other drivers will have no idea what you are up to and may respond in a variety of ways ranging from fear to curiosity to aggression.  A police officer will probably not understand when you try to explain why you were driving erratically!  Zeckhausen Racing does not endorse speeding on public roads and takes no responsibility for any injuries or tickets you may receive while following these instructions.  Use common sense!

1. From 60mph, gently apply the brakes a couple of times to bring them up to operating temperature.  This prevents you from thermally shocking the rotors and pads in the next steps.

2. Make eight to ten near-stops from 60mph to about 10-15 mph. Do it HARD by pressing the brakes firmly, but do not lock the wheels or engage ABS.  At the end of each slowdown, immediately accelerate back to 60mph and then apply the brakes again.  DO NOT COME TO A COMPLETE STOP!  If you stop completely and sit with your foot on the brake pedal, you will imprint pad material onto the hot rotors, which could lead to vibration and uneven braking.

3. The brakes may begin to fade after the 7th or 8th near-stop. This fade will stabilize, but not completely go away until the brakes have fully cooled.  A strong smell from the brakes, and even some smoke, is normal.

4. After the last near-stop, accelerate back up to speed and cruise for a while, using the brakes as little as possible.  The brakes need only a few minutes to cool down.  Try not to become trapped in traffic or come to a complete stop while the brakes are still very hot.

5. If full race pads, such as Hawk DTC-70 or Performance Friction PFC01 are being used, add four near-stops from 80 to 10 mph.

After the break-in cycle, there should be a slight blue tint and a light gray film on the rotor face. The blue tint tells you the rotor has reached break-in temperature and the gray film is pad material starting to transfer onto the rotor face. This is what you are looking for.  The best braking occurs when there is an even layer of of pad material deposited across the rotors.  This minimizes squealing, increases braking torque, and maximizes pad and rotor life.

After the first break in cycle shown above, the brakes may still not be fully broken in.  A second bed-in cycle, AFTER the brakes have cooled down fully from the first cycle, may be necessary before the brakes really start to perform well.  This is especially true if you have installed new pads on old rotors, since the pads need time to conform to the old rotor wear pattern.  If you've just installed a big brake kit, the pedal travel may not feel as firm as you expected.  After the second cycle, the pedal will become noticeably firmer.  If necessary, bleed the brakes to improve pedal firmness.