Rotors, seasoning rotors, carbon metallic pads, etc...

[audi]

At a recent DE, I realized my factory front pads were getting thin; not having thought to bring a spare set, a quick paddock survey turned up a used but decent set of front Performance Friction pads. They worked *great* for the remainder of the DE, but are a bit noisy for the street.

My understanding is it's not recommended to switch back to organic pads once you've used carbon metallic pads on a given set of rotors.

So my questions are: how absolute a rule is it not to switch back to a more streetable pad on those rotors? My understanding is the CM pad leaves the rotor surface such that an organic pad doesn't work as well as it should, or something like that. My front rotors are getting to where replacement isn't a bad idea, so that's what I'll do, but I'm curious as to what people think who know more about this stuff than I do.

For new rotors, does anyone "season" them prior to installation (I've read about beadblasting the surface, etc.) or is it acceptable to just replace them?

Having read through as many pad threads as I could, I decided to give the Porterfield R4S a try, so I ordered them. Maybe this is a dumb question, but is there anything wrong with bedding a brand new set of pads on brand new rotors, or are there any particular "bed-in" things to pay attention to when replacing both rotors and pads at the same time? At this point, I was going to replace only the front rotors, but do the pads on all 4 corners.

Thanks in advance.

[SilberUrS6]

Originally Posted by audi

For new rotors, does anyone "season" them prior to installation (I've read about beadblasting the surface, etc.) or is it acceptable to just replace them?

I don't know about your other questions, but I'll tell you my practice with rotors.

I buy a set of rotors a year before I intend to install them. I spray a little silicone oil on them, and let them sit flat on a wooden shelf under my work bench. When I am ready to use them, I hose them down LIBERALLY with brake cleaner to get all the silicone off. I then install and bed as normal.

I had read, many years ago, that cast iron rotors take a long time to finalize the crystal structure. I have never looked it up to prove it to myself, but my practice has served me well over the years, if for no other reason than when I felt the desire to do the swap, I had a part waiting.