Brake Rotor "Warping"

Charlie Guthrie · **Joined:** Thu Aug 28, 2003 8:14 pm **Posts:** 832

the fine folks at FCP have my email address and send way too much "instructional" information for the auto enthusiast. Unfortunately for me I happened upon their website while researching various prospects for our next rally-beater and I was getting a flavor for the cost and availability of various cars. so now I get bulletins for cars that can be had for a song such as oddball models of Volvo and Mitsubishi.
and now for the point of this post.... this link is to a layman's explanation of brake rotor vibration. I have read other descriptions of pad material transfer, but this one is not meaty, just the fluffy stuff.
http://blog.fcpeuro.com/2014/08/08/warped-rotors-reality-or-myth/
Charlie G

RickyBeam · **Posted:** Mon Sep 08, 2014 4:06 pm

I can personally attest to the brakes not being the sole reason for a car to "shutter" under braking. Ride in the Duff car with blown shocks... under hard enough braking, the wheels literally bounce off the surface as the springs are the only thing working. (went sailing off the end of T1 at VIR because of it. My instructor (Tom Hart I think it was) thought we could've still made the turn, but I'll not risk it -- esp. at an HPDE.)

Matt McGrain · **Posted:** Mon Sep 08, 2014 4:30 pm

Thanks for sharing, and this pretty much reaffirms what I've heard through the years on the Honda forums, which you take with a grain of salt most of the time.

If you don't have any vibration upon wearing out a set of pads, is it ever detrimental to not have the rotors resurfaced? I never have, but then again I don't keep cars as long as I probably should.

Also, can anyone recommend an inexpensive digital micrometer to gauge rotor thickness? I have my doubts about the Harbor Freight offering. :lol:

JamesMilko · **Posted:** Mon Sep 08, 2014 5:04 pm

Matt McGrain wrote:

Thanks for sharing, and this pretty much reaffirms what I've heard through the years on the Honda forums, which you take with a grain of salt most of the time.

If you don't have any vibration upon wearing out a set of pads, is it ever detrimental to not have the rotors resurfaced? I never have, but then again I don't keep cars as long as I probably should.

Also, can anyone recommend an inexpensive digital micrometer to gauge rotor thickness? I have my doubts about the Harbor Freight offering. :lol:

I got the HF one that is "good" to .0001. I checked it against my Craftsman feelers and it was dead on. I figured I needed accuracy to the thousandth so if I got one that was an order of magnitude more accurate it was likely ok for what I needed.

It doesn't open enough for the rotors on the GTO though.

Charlie Guthrie · **Joined:** Thu Aug 28, 2003 8:14 pm **Posts:** 832

Just buy the digital calipers at $15 (approx); they are accurate to 0.001 which is more than enough for rotors, and they are more handy than micrometers. Just make a habit of removing the batteries because they seem to drain.

Matt McGrain · **Posted:** Mon Sep 08, 2014 8:33 pm

Good to know guys. As always, I'll file the receipt for the good ole H-F no questions asked exchange if needed. :thumbsup:

Roger McDaniels · **Posted:** Thu Sep 18, 2014 2:48 pm

HF also has a mechanical dial caliper that's accurate to .001". I bought it because I got tired of dealing with the batteries in the digital one. I like it better than the digital one.

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Brake Rotor "Warping"

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