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Brake Pad and Rotor Bed-In Procedures

Also know as Burnishing or Breaking In


All brake pads must be bedded-in with the rotors they will be used against to maximize brake performance. Until they are properly bedded in, your brakes simply do not work as well as they can. Proper brake pad and rotor 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.

The bedding-in process involves a gradual build up of heat in the rotors and pad compound. This process lays down a thin layer of transfer film on to the rotor surface. Following the bed-in procedures provided will assure a smooth, even layer of transfer film on the rotor and will minimize brake judder.

Here are a few things to keep in mind when installing new rotors and pads:


1. When installing new pads, the rotors should be new or at least resurfaced to remove any transfer film from the previous set of brake pads.

2. It is critical that the installer clean any rust, scale, or debris from the hub mounting surface thoroughly and check it for excessive run-out with a dial indicator gauge before installing the rotor. Failure to have a flat, even, and clean surface will cause the rotor to warp when it is tightened to the hub.

3. The new rotors should also be checked for excessive run-out using a dial indicator gauge before the caliper and pads are installed. If a rotor has excessive run-out of over .004" (.10mm) it should be replaced. Using a rotor with excessive run-out on the hub or rotor will cause vibration and pulsation issues.

4. Failure to follow these procedures may result in brake judder, excessive noise, or other difficulties in bedding-in the new brake pads. The pads need a fresh surface to lay down an even transfer film. Residue from the previous pad compound on the surface or an irregular surface on a used rotor will cause the pads to grip-slip-grip-slip as they pass over the rotor surface under pressure. The resulting vibration will cause noise and telegraph vibrations through the suspension and steering wheel. This vibration is known as brake judder or brake shimmy. This is typically caused by an uneven transfer film on the rotor surface or an uneven surface on the rotor not allowing that transfer film to develop evenly. This is often misdiagnosed as a warped rotor.

5. 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.

Bedding-in new pads and rotors should be done carefully and slowly. Rapid heat build up in the brake system can lead to warped rotors and or glazed brake pads. Most brake pad compounds will take up to 300-500 miles to fully develop an even transfer film on the rotors.

The bed-in procedure for street brake pads is as follows:


1. This step transfers pad material onto the rotors.
          Make 10 stops from 30 mph (50 kph) down to about 10 mph (15 kph) using moderate braking pressure and allowing approximately 30 seconds between stops for cooling. Do not drag your pads during these stops. After the 10th stop, allow 15 minutes for your braking system to cool down.


2. This step completes the curing of the brake pad's friction material.
          Make 5 consecutive stops from 50 mph (80 kph) down to 10 mph (15 kph). After the 5th stop, allow your braking system to cool for approximately 30 minutes. This completes the break-in of your pads to the rotor surface.


During Steps 1 & 2, a de-gassing process occurs which may produce an odor coming from your pads as they complete the break-in cycle. This odor is normal and is part of the process your pads must go through to achieve their ultimate level of performance. The odor will go away after allowing your braking system to cool for approximately 30 minutes.

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.

As with any new set of pads, do not tow a trailer or do any hauling during the break-in period.

Full seating of your new brake pads normally occurs within 1,000 miles.

Read and understand these bedding instructions completely before starting. If you have questions, give us a call or email.