"Bedding In" New Brake Pads

[Shannow]

Back in the 70s, Oz racing teams were trying to pre-bed pads in so that they could change them during the race, and not stuff them inside a couple of laps, or suffer diminished performance.

One team developed a theory that it it was the outgassing of the binders that caused the problems early, so developed a rig with a thinned down cast iron flywheel, that they heated to near red, then clamped the new pads to the flywheel with a brake caliper.

Watched the "ash" line migrate from the friction surface, and when it reached 1/4" from the friction face, they took the pads off and let them cool.

Apparently worked better than pre-bedding them, as the disk surface changed during the race.

 

[moribundman]

Originally Posted By: The Critic
The 30/30/30 (or similar method) allows the pads to seat. It's important because doing 30 stops in a row (with cool down) heats up the pads enough so that the material transfer may occur. Normal driving may not heat up the pads enough to allow this process to occur.

GM had a method that was similar to the 30/30/30 for the exact problem that you described:

"Rotor refacing for cosmetic corrosion is unnecessary. Clean up of braking surfaces can be accomplished by 10-15 moderate stops from 62-75 km/h (35-40 mph) with cooling time between stops."

http://www.procutinternational.com/supplier_gm.aspx


I didn't describe any problem. Or are you not replying to me? You'll have to accept that I will follow the manufacturer's instructions, which has always worked for me. I'm not the one with wobbly rotors, squeaky pads and other signs of shoddy work or lousy gear.

 

[Shannow]

Got to admit, whenever I change the pads, I do a few laps of the block, running down "Hospital Hill" at moderate speed and high brake load.

Doing the circuit ensures that I don't come to a full stop at any point for the half dozen laps. Never had a squeak, shimmy or anything.

Only changed three sets of pads on my cars in 12 years of being in this house.

I just don't wear them out.