Iowa999

iTrader: (1)

I had an interesting conversation with a local shop - the one that is supposed to be the best in the area for brakes. I came in asking for him to swap the pads on my 2008 GSR. I made it clear that these were not the same pads as on the car.

The shop-owner did not seem to want to do the job. He referred to it as a "pad slap" and said that, for the sake of his reputation, he wouldn't do the job because I wouldn't be happy with the results.

I asked him what he would suggest, instead, since I'm at the wear-indicators, so I need to replace the pads, and I don't want to put a new set of OE pads on.

He said that he would only do it if he also turned the rotors.

I asked if that was because of the difference in pad compounds or because of the scratches on my rotors from the wear indicators or what.

He then stepped back and switched to a very condescending tone, repeating that he has his reputation to think about, etc, but didn't actually say why he would turn the rotors.

Since I was on the edge about turning the rotors, anyway (for a variety of reasons), I went ahead and asked him to do the entire job.

With that very long-winded set-up out of the way, here are my questions: Assuming that there is no other reason to turn the rotors, would you go ahead and turn them, anyway, if you were changing pad compounds? (If my case, it's from OE to Posi-Quiet semi-metalics, if that makes a difference.) I'm pretty sure that track folks often do what this shop-owner calls a "pad-slap" (i.e., change pads without doing anything else), but could someone verify that this really is done, at least when the new pads are the same compound as the old? Or do track guys also turn the rotors every time you change pads, even when keeping the compound the same?

Montu

iTrader: (2)

Track guys don't need to turn the rotor going to a track pad because the track pad is so abrasive it just sheers off the old pad deposits.

when switching from track to street compound or street to street then yes its a good idea to turn the rotors...but you can always take your chances and most of the time if you do a good bed in or sand down the rotors your self in the sink its good enough.

so yes his recommendation is actually correct if you want the best results.

ugakirk

iTrader: (14)

You don't have to if you bed them in really good. I didn't turn my rotors when I replaced my pads. I would suggest that next time you learn how to replace the pads yourself. It is VERY, VERY easy on these cars..

Anyway, this way it ensures that you get a nice, clean braking surface to bed the pads in and you shouldn't have any problems..

Iowa999

iTrader: (1)

That goes well with my reading of the situation. (Warning: my day job [psychologist] is about to kick in here.) I think that he has a memorized set of rules for what to do under which situations. My situation called for turning the rotors, so he said he would only do the job if I let him do this, too. The "tone" of the conversation, coupled with the fact that he wouldn't tell me why the rotors needed to be turned, implies to me that he became defensive and, therefore, a tad aggressive and condescending, because he doesn't actually know why the rotors need to be turned ... that's just what he was trained/told to do in my situation.

In any event, given that his lathe guy is supposed to be the best around and you all (so far) are cool with the idea of having the rotors turned, I'm glad I said yes.

But more responses welcome, because I'd like to know more.

Iowa999

iTrader: (1)

Oh, I could do it, no problem. Normally I do all work on my cars. I'm just very busy and I was concerned about the scratches from the wear-indicators, so I stopped in at the shop. I also like meeting all the shop-owners in an area, to get a "feel" for how they approach their work. I'm new to Iowa City, so this seemed a good time to meet the local "brake expert."

Vivid Racing

iTrader: (98)

That kind of response is off from a shop owner. I could see that from a young tech, though. Unfortunately a lot of technicians forget all the actual theory as soon as the leave school. They've memorized the procedures, and that's all that matters to them.

As the folks above said, the reason track guys don't do it is because with their aggressive driving, it's not so much an issue. Also, track guys don't follow the break-in procedures for clutches.

There's no harm in machining the rotors, other than the hit to the wallet. I've always recommended doing it when doing brakes on a street car.