[cboy]

While doing a search regarding brake pads I ran across a thread that noted the importance of properly "bedding in" new brake pads. Unfortunately there was no further discussion about the process. So what's the "proper" way to break in new brake pads (going on with new rotors BTW).

[gcrmcc]

Don't know if i'm right or not but what I was told when I was 17 and working in a small independent shop was to go drive about 40mph and apply light pressure untill you feel a little drag then release again and do it several times but not to the point of getting the brakes to hot or they will glaze up. I have done this now for 34 years on new brake installs and never had a complaint later from any one.

gcrmcc

[curtis73]

Close. Manufacturers recommend different things based on their pad construction, but its basically very similar.

You want to get the pad fully hot, not just on the surface. This heat treatment causes the pads to reach their final composition uniformly. When they "burn" inside the pad, they don't burn onto the rotor which is what causes brake pulse... NOT "warped" rotors.

Find a deserted road. Its important to do this immediately after the pads are put on. The proper way to bed in pads is to get the car up to speed; whatever is safe for your environment; lets say 50. Hit the brakes hard; almost to the point of locking them up but don't let them lock. Before you come to a complete stop, let off the brakes. Take it back up to 40 or so and do it again. Then 30 and 20. You can overdo it, but it takes a long while. I would say three times through that cycle (a total of 12 hard braking cycles) should bed them properly. On the ride home, though, I still recommend against coming to a complete stop with the brakes applied. They are screaming hot; much hotter than they will get in normal driving. The best way to do it is to drive long distances without stopping to get the brakes back down to normal operating temperature before you stop. If you must stop, use the parking brake, the transmission, a hill... whatever to stop yourself and then let them sit for several hours until they cool off.

What you are trying to do is get the pads hot without stopping the motion. The cause of brake pedal pulse is not warped rotors, its pad material that gets deposited on the rotor altering its thickness and friction properties. Most people put on new pads and come to a complete stop. The fresh pad material does its burning while in stationary contact with the rotor. It deposits its carbon on the screaming hot casting. Now your fresh rotors and new pads have a pulsation that people blame on warped rotors.

Following that bedding procedure evenly deposits a little bit of pad material without burning on small spot. It also superheats the pad chemically altering it which means it won't be depositing large quantities of fresh pad material on your rotors.