Seems like I recall folks sometimes use either emory paper or fine sandpaper on a drill attachment or DA and lightly sand off the swept area of rotors (or flywheels for clutches?) and 'brighten' them up when replacing pads. That is presuming they aren't overly grooved, warped etc...
But then I've heard this is not worth doing - simply do nothing when replacing pads.
What's the scoop here?
It's okay to do this, using fine sandpaper, to break the glaze.
They will eventually seat in anyway, but if you deglaze them, they are probably a bit quieter at first, might seat in a little faster.
||Seems like I recall folks sometimes use either emory paper or fine ||sandpaper on a drill attachment or DA and lightly sand off the swept ||area of rotors (or flywheels for clutches?) and 'brighten' them up ||when replacing pads. That is presuming they aren't overly grooved, ||warped etc... || ||But then I've heard this is not worth doing - simply do nothing when ||replacing pads. || ||What's the scoop here?
The reason shops do this is to impart a non-directional finish pattern after turning the rotors on a lathe. A lathe bit cuts is a very fine spiral from hub to outside. This pattern can present a "thread" to the pad, such that it can kick the pad against the caliper bracket when brakes are applied (taking up the slack). In paractice, this is a rare problem and a minor annoyance at best. I've never sanded rotors, whether I've turned them or not, and never had a problem. Rex in Fort Worth
I do it on every brake job. I've seen manufacturer videos and had automotive instructors advise it.. Minor annoyances cause "come backs."
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My Ford shop manual says to lightly sand the rotors when replacing pads. It goes on to say to never turn rotors - if they are deeply grooved, replace them. It suggests using degreaser and lightly sanding the new ones, too.
I haven't turned rotors since I first began doing my own car work. I have sanded some fairly grooved discs when replacing pads and still got good braking and reasonable pad life.
I hope this helps some - PoD
||On Fri, 23 Apr 2004 20:15:24 GMT, snipped-for-privacy@REMOVEtxol.net (Rex B) ||wrote: || ||>On Thu, 22 Apr 2004 21:56:25 -0500, pgtr ||> wrote: ||>
||>||Seems like I recall folks sometimes use either emory paper or fine ||>||sandpaper on a drill attachment or DA and lightly sand off the swept ||>||area of rotors (or flywheels for clutches?) and 'brighten' them up ||>||when replacing pads. That is presuming they aren't overly grooved, ||>||warped etc... ||>|| ||>||But then I've heard this is not worth doing - simply do nothing when ||>||replacing pads. ||>|| ||>||What's the scoop here? ||>
||>The reason shops do this is to impart a non-directional finish pattern after ||>turning the rotors on a lathe. A lathe bit cuts is a very fine spiral from hub ||>to outside. This pattern can present a "thread" to the pad, such that it can ||>kick the pad against the caliper bracket when brakes are applied (taking up the ||>slack). In paractice, this is a rare problem and a minor annoyance at best. I've ||>never sanded rotors, whether I've turned them or not, and never had a problem. ||>Rex in Fort Worth || ||I do it on every brake job. I've seen manufacturer videos and had ||automotive instructors advise it.. Minor annoyances cause "come ||backs."
In a professional setting, you have to do it. One comeback can kill the profit for several brake jobs, so you cannot take the chance. For an individual working on his own car, it's different. Rex in Fort Worth
Agreed. But it's really trivial to sand the rotors and put a non-directional swirl on them. For the individual, just ask the shop machining your rotors to sand them for you.. In all likelyhood, they've had the request before.
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