Jim Smart
September 1, 2000

What Is Rotor Seasoning?
According to Baer Brake Systems, disc brake rotor seasoning is a vital first step with new rotors. Think of it like you would the molding of a baby’s personality because you will certainly be stuck with the results if you don’t handle it properly. Seasoning new rotors is important because it molds the molecular structure of the iron/steel. When we properly season new rotors, we’re burning the factory machine oils off of the surface and establishing a pad/rotor marriage.

The most complex break-in task is relieving the internal stresses within the iron/steel. If this is hard to understand, think of it like you would pouring water into a glass of ice. The casting and cooling of the iron leaves the material with internal stresses you don’t need. How to relieve stress? Here’s what Baer suggests.

  • Drive the vehicle for five or six days without heavy braking. Normal braking helps relieve internal stresses because we’re cycling the iron from cold to hot and back to cold again. Baer adds that zinc-plated rotors take even more time.
  • Find a safe location where you can get those brake temperatures way up.
  • You want to gradually increase brake temperature with progressively faster stops. Begin with 60 to 70 mph stops as you would in normal driving. Do not slam on the brakes.
  • Next, perform four medium effort partial stops from 60 mph down to 15 mph. Follow this with five minutes of highway driving with little or no braking.
  • Next, perform four medium to hard effort partial stops from 60 mph down to 15 mph. Follow this with 10 minutes of open highway driving, with little or no braking, to allow the rotors to cool.
  • Park the vehicle and allow the brakes to cool overnight. You’re halfway there.
  • Return to the safe location and get your brakes up to temperature. Make sure the brakes are warm. Repeat the same procedure you did the day before. First, four medium pedal effort stops from 60 mph down to 15 mph. Again, follow this with five minutes of highway driving for brake cooldown.
  • Again, perform four medium to hard effort partial stops from 60 mph down to 15 mph. Follow this with 10 minutes of open highway driving for another brake cooldown.
  • Next, get your Mustang up to 60 mph and do six very hard partial stops down to 15 mph. Brake rotor temperature should be 900 to 1,100 degrees F. Baer sells a special paint that indicates brake temperature. Follow this sequence with 10 minutes of open highway driving for brake cooldown.
  • Allow brakes to cool overnight.
  • With the rotors properly seasoned, we’re ready to bed the pads. Bedding the pads is important because it marries the pad to the rotor. The friction material in semi-metallic brake pads is held together by an organic binder. As the pad gets hot, the binder tends to boil and burn. As this occurs, the friction material makes better contact with the rotor. Racing pads, like those we see from Performance Friction, lay down a layer of carbon on the surface of the rotor. This is necessary for these pads to perform well.
  • Always follow this procedure exactly. No short cuts. This process of rotor seasoning and pad bedding allows pad and rotor to mate comfortably for a pleasant service life that will serve you well.