This is a discussion on Brakes Shake after new pads? within the General Maintenance, Troubleshooting & Accidents. forums, part of the Tech & Modifying & General Repairs category; Originally Posted by Donkey Stoptech has some great technical articles on their site: StopTech : Balanced Brake Upgrades StopTech : ...
Yep, thanks Ron those are excellent links. I had read them in the past a couple of times.
Kevin, they actually do not recommend having rotors "turned" or "milled" anywhere in there - tossing on a lathe at a corner garage is not "blanchard grinding"
"The obvious question now is "is there a "cure" for discs with uneven friction material deposits?" The answer is a conditional yes. If the vibration has just started, the chances are that the temperature has never reached the point where cementite begins to form. In this case, simply fitting a set of good "semi-metallic" pads and using them hard (after bedding) may well remove the deposits and restore the system to normal operation but with upgraded pads. If only a small amount of material has been transferred i.e. if the vibration is just starting, vigorous scrubbing with garnet paper may remove the deposit. As many deposits are not visible, scrub the entire friction surfaces thoroughly. Do not use regular sand paper or emery cloth as the aluminum oxide abrasive material will permeate the cast iron surface and make the condition worse. Do not bead blast or sand blast the discs for the same reason.
The only fix for extensive uneven deposits involves dismounting the discs and having them Blanchard ground - not expensive, but inconvenient at best. A newly ground disc will require the same sort of bedding in process as a new disc. The trouble with this procedure is that if the grinding does not remove all of the cementite inclusions, as the disc wears the hard cementite will stand proud of the relatively soft disc and the thermal spiral starts over again. Unfortunately, the cementite is invisible to the naked eye."
"From a little spark may burst a mighty flame." - Dante
"The stitch is lost unless the thread is knotted." - Italian proverb
There used to be a product that you inserted on the face of the new pads during a new install. It basically wiped the rotor free of contaminants and cementite. Basiclly kinda what EBC puts on their brakes but this was a very thin "brake in pad" that just wore away as apposed to a coating.Not sure if they were effective or not. Can't find any info on them. I often wondered if blasting the rotor faces with aluminium oxide would work.
Last edited by Donkey; 11-20-2009 at 03:07 PM.
20-40 dollars to turn the rotors, vs 120-800 to replace the rotors... that's all I'm saying.