Re: [DML] brake runout specs (revisited)

["Walter Coe" <Whalt@xxxx>]

> For the sake of getting your money's worth out of your premo rotors, why
not > cut them as much as you can without exceeding the minimum thickness.
If
> there is some part untouched by the knife, sand and deglaze and try to
blend
> or match the surface texture so as to avoid slip/grads on application.

Don,

Uh, no. :-) I'm no brake expert, but I do know that the rotor surfaces
require a high amount of precision. I'm sure that just knocking off the
high spots would not work well.

I talked with Rob Grady today about the rotors. He explained that there is
only one company that makes them, and they are in Europe. He said that he
has been selling this brand of rotor for a long time and has never had a
complaint. My only complaint is from what I could see, but in use on the
car I can't feel any symptoms of runout whatsoever. It seemed reasonable to
me that so much runout would cause the pistons in the calipers to wear out
prematurely, but Rob explained that this isn't the case. He explained the
way the piston floats in the calipers and doesn't wear the bore. That
information and with what David T explained, I decided to leave it well
enough alone. I thought that I might have seen a slight glaze on the rear
rotors, so I sanded them down with 80 grit while they were still on the car.
It's a tight fit to reach the backside, but a bigger hassle to take them
off. From my limited experience with brake glazing, apparently there was a
slight layer of glaze that needed to come off. I should have been more
careful with the break-in, but it is rather hard to drive a car gently when
it really likes to go fast. Hey, it's not my fault the car a personality.
:-)

Walt Tampa, FL