ZoominTeg

When I drive normally, like on a highway, my steering wheel is fine, but when I start stopping hard or after racing, the steering wheel begins to shake. Only happens once I hit the brakes. Once I let go, the wheel doesn't shake. Any tips? New pads maybe? Or Rotors? Or Alignment?

Ron Carroll

Your Front brake rotors are warped, replace them, resurfacing will only fix the problem for a short while and then they will warp again.

Wraith_G2IC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itaintegra31 &raquo;</TD></TR><TR><TD CLASS="quote">Your Front brake rotors are warped, replace them, resurfacing will only fix the problem for a short while and then they will warp again.</TD></TR></TABLE>

No, that is not true. Very common misconception. I wish I could get to G2IC to pull up the link that Ben Ogle gave me over there. It wes to a racing guru (Carol Smith I think). What he boiled it down to is that there are acouple of conditions that cause this . The most common was pad material build up on the surfase of the rotor. A very small amount will cause the shudder condition. The most important thing to do is properly bed your new brakes in. When I find the link I will post it up. I think it will make alot of sense.

ZoominTeg

That would be great, btw, what do you mean bed?

xSCTYGx

bleed maybe?

Wraith_G2IC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2Gen91Teg &raquo;</TD></TR><TR><TD CLASS="quote">bleed maybe?</TD></TR></TABLE>

No, "bedding" is a term used to identify the process of getting your pads set in the calipers. It also wears the initial coating off of the pad to ensure even contact with the rotor. I will look to see if I have the page marked. G2IC.com is down, so I can't just go get it. I remember there is a book he wrote TUNE TO WIN by Carroll Smith.

tobeS2000

i believe u mean "breaking in" the rotors (and or pads, depending on if u replace them as well or not) this is done by getting the car up to crusing speed (about 45mhp) then riding the brake for 1/4 mile to heat up the new pads so they will mate with the rotor's new surface. After resurfacing the rotors they will re-warp no faster than the original surface on the rotors did, unless u drive the car harder than u did before. The rotors warp b/c of excessive heat build-up and incessent hard braking.

tobeS2000

oh and by the way..... to get "your pads set in the calipers" all u have to do is pump the brake after u put the brake assembly back together...what this does it sets the pistons within the caliper to their correct position with pads so they rub the disc only enough to keep the pads in the correct position while not braking....if you are not doing the work by yourself you don't need to worry about this the shop will take care of this and the other small details of a brake job for you

Wraith_G2IC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tobeS2000 &raquo;</TD></TR><TR><TD CLASS="quote">i believe u mean "breaking in" the rotors (and or pads, depending on if u replace them as well or not) this is done by getting the car up to crusing speed (about 45mhp) then riding the brake for 1/4 mile to heat up the new pads so they will mate with the rotor's new surface. After resurfacing the rotors they will re-warp no faster than the original surface on the rotors did, unless u drive the car harder than u did before. The rotors warp b/c of excessive heat build-up and incessent hard braking. </TD></TR></TABLE>

Well, you believe wrong. Rotors do not warp. Perhaps I didn't mention that English IS my 1st language. I meant what I said. If want, you may refer to bedding as a "break-in period". And the method you mentioned of riding the brakes at 45 MPH may work too. If you read the instructions that come with performance pads, they will suggest the best method.

I will have to admit that until a short time ago I believed rotors warped too. That is until I was pointed to a more scientific explanation. I know some of you guys watch CSI.... let the science tell the story. Please, everyone read this article on StopTech's web site written by Carroll Smith (a long time racing tuner)

http://stoptech.com/whitepaper...h.htm

obsidianG35

Yes, bedding is the correct term...

here are some instructions.
http://www.baer.com/Support/Te...pID=5

Solracer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Wraith_G2IC &raquo;</TD></TR><TR><TD CLASS="quote">Well, you believe wrong. Rotors do not warp. </TD></TR></TABLE>

Well Said Wraith, if you look at how much metal is in any rotor, do you people realize how hot you would have get the rotor for to truely warp? Probaly so hot that you would melt your caliper seals and most of the rubber around the wheel well area.

Things to avoid having material build up on your rotors, when your rotors are hot, do not ride them drive slowy and let them bleead the heat of, also do not set your parking break either as this will do the same to the back rotors.

Ron Carroll

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Solracer &raquo;</TD></TR><TR><TD CLASS="quote">

Well Said Wraith, if you look at how much metal is in any rotor, do you people realize how hot you would have get the rotor for to truely warp? Probaly so hot that you would melt your caliper seals and most of the rubber around the wheel well area.

Things to avoid having material build up on your rotors, when your rotors are hot, do not ride them drive slowy and let them bleead the heat of, also do not set your parking break either as this will do the same to the back rotors.</TD></TR></TABLE>

Have any of you people ever put a dial indicator on a rotor before ? If you had you would know that rotors do warp and it is caused by a number of things, excisive torquing of the lug nuts and heat are 2 of them. I have been in the automotive repair bussiness for a long time and belive me rotors do warp.

KilaB18C

Sounds like you might have some hot spots in your rotor

91integraLSVTEC

dont mean to get off topic, but what if grease and stuff gets on the rotor? i did an axle change and didnt care about the grease on the rotors until i drove my car, the braking power sucked after awhile it came back though.. will that cause rotors to warp or cause damage to the brakes?

Wraith_G2IC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Solracer &raquo;</TD></TR><TR><TD CLASS="quote">Well Said Wraith, if you look at how much metal is in any rotor, do you people realize how hot you would have get the rotor for to truely warp? Probaly so hot that you would melt your caliper seals and most of the rubber around the wheel well area.</TD></TR></TABLE>

Thank you. Sounds like we have a auto-crosser here. It also looks like I need some support to inform the others.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itaintegra31 &raquo;</TD></TR><TR><TD CLASS="quote">Have any of you people ever put a dial indicator on a rotor before ? If you had you would know that rotors do warp and it is caused by a number of things, excisive torquing of the lug nuts and heat are 2 of them. I have been in the automotive repair bussiness for a long time and belive me rotors do warp.</TD></TR></TABLE>

Hmmmmm........ sounds like someone didn't do the assigned reading.

And I quote - "in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history- I have never seen a warped brake disc." "The driver can feel a 0.0004" deposit or TV on the disc. 0.001" is annoying. More than that becomes a real pain. When deposit are present, by having isolated regions that are proud of the surface and running much hotter than their neighbors, cementite inevitably forms and the local wear characteristics change which results in ever increasing TV and roughness."

Does anyone else think this difference could be measured with a dial indicator?

Solracer

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Wraith_G2IC &raquo;</TD></TR><TR><TD CLASS="quote">Hmmmmm........ sounds like someone didn't do the assigned reading. </TD></TR></TABLE>


Yeah there not reading go figure, deposit mean leaves material on the rotor, if you run a dial on rotor, of course you are going to see movemnt every time you hit an area where the deposists are. I have turned rotors on a lathe, if you watch when they are turning the rotor pretty much spins perfectly but you can here the blad hit the high sports, which are the area's where the deposits are.

Running better pads, epsically semi-mettalics will help with this not happening, I have been autocross and HPDEing for the past 5 years, since I have taught myself hot to treat my brakes nice, I have not "warped" a single rotor. I can tell you fro a fact that braking from 115 to 45 in turn 1 at VIR for 2- or 25 laps three times a day will get my brakes way hotter than anything you can do on the street.

Sukebei Oni

wow, so much miss information in this thread.

first off, rotors do warp. They can warp from many different factors, Such as uneven pad wear, uneven pressure, hung caliper, heat, an so on. You can check it with a dial indicator like said above, but you should put them on a brake machine and recut them anyways when ever you change the pads.
just pumping the brake pedal does not break in the pad. it will take up the slop from the installation. Then to seat the pads, drive the car easy at first, making slow easy stops. gradualy making easy stop from greater speed.
I'm done for now.
I swear there is too many people here that don't really know what there talking about and spread miss information.

note: this does not apply to aftermarket fast and furious parts.

as for the high spots caused by deposit build up, this may be true. but since the rotor now has high spots, and is outoff round, it can be given the term warpped. and thus needs to be cut.

Wraith_G2IC

I give up.

For the rest of you out there who don't still believe the world is flat, please read the articles mentioned above. Trust the authors of these articles, they are experts. We mere mortals, armed with a dial indicator and some preconceived notions might have been wrong.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sukebei Oni &raquo;</TD></TR><TR><TD CLASS="quote">wow, so much miss information in this thread.
I swear there is too many people here that don't really know what there talking about and spread miss information.</TD></TR></TABLE>

The preceding comments were brought to you by "The Keeper Of All Knowledge", and in no way reflect the opinions of this board and it's supporters.

Sukebei Oni

riddle me this.

If you believe what they say, that the area inbetween the vains of the rotor can colapse when the brakes are applied at high temps. Than how can you say that the rotor cannot be warpped at high temps as well. That webpage just looks like an Ad to me anyways.

Wraith_G2IC

Here is how you solve the "riddle", with the law of averages:

Assume for a minute that 50% of the members here on this board have experienced some sort of brakes shudder (and I think that is a low number).
Now take into account that most all of us drive in some type of stop and go traffic and hit the highways regularly.
And a "small" percentage of all of us street race (not auto cross, that is totally different).
Now does anyone out there think that they can abuse their rotors, like Solracer mentioned, to the point of being so hot we can hold a H-T barbecue on them? I suspect that if you can, or have, then you are counting down the days until you get your license back.

The pic you pulled was taken out of context from the article.

From the article: "- I have never seen a warped brake disc. I have seen lots of cracked discs, (FIGURE 1) discs that had turned into shallow cones at operating temperature because they were mounted rigidly to their attachment bells or top hats, (FIGURE 2) a few where the friction surface had collapsed in the area between straight radial interior vanes, (FIGURE 3) and an untold number of discs with pad material unevenly deposited on the friction surfaces - sometimes visible and more often not. (FIGURE 4)

In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures."

Figure 3 is the pic you posted. Please note that the sentence includes the words "a few". This man, in more than 40+ years of racing experience, has seen "a few" examples of a collapsed rotor under the MOST EXTREME conditions that we will not even come close to.

Now if no one has been following the math.....
How do you get from "a few" examples of collapsed rotors over 4 decades to a large percentage of us out here on the street experiencing "warped" or collapsed rotors.
The answer - you don't.

Solracer

Are those Crickets I hear? heheh