kuryakin Posted January 5, 2009 Share Posted January 5, 2009 So, I have an 05 GT wagon, stick shift, warped front rotors, cut then replaced by the dealer, warranty expired, I replaced them with slotted and drilled front rotors, and now they're warping AGAIN! So, anyone have ANY success finding a permanent fix that doesn't cost a fortune? Link to comment Share on other sites More sharing options...
05GT Guru Posted January 5, 2009 Share Posted January 5, 2009 I had the stock ones warp on me, i now have slotted and have not had any problems since. How many miles are on these new rotos? Do you track the car? If you dirve the car nicely and dont have that many miles on your rotors then i would say its a problem with equal pressure, check your calipers out. Link to comment Share on other sites More sharing options...
Guest Posted January 5, 2009 Share Posted January 5, 2009 Rotors almost never warp. It's the pad deposits. Ceramic pads in general, particularly crappy stock ones, often are prone to this. Buy new pads, rebed them and you should be fine. Link to comment Share on other sites More sharing options...
WhatV8 Posted January 5, 2009 Share Posted January 5, 2009 I can't think of any 'inexpensive' brake system fixes. How are you using your vehicle (i.e.- spirited street driving, track days, auto-x, towing, etc)?? Sounds like you need to better match your equipment to your application. BTW, cross-drilling does nothing to help matters if you are in fact warping your rotors. Slotting is usually only necessary for extremely wet applications. To keep as much mass/strength in the rotors you need to keep the material that the cross-drilling and slotting removes. You can read up on this on Baer's Eradispeed and DBA's websites. Lastly, are you sure you are really warping your rotors? Glazing the rotors will give a similar pedal feel and steering wheel chatter. This can be corrected with a different pad compound and proper bedding technique. Link to comment Share on other sites More sharing options...
05GT Guru Posted January 5, 2009 Share Posted January 5, 2009 Yes but glazing goes away after a couple hard hits from the pads. Link to comment Share on other sites More sharing options...
WhatV8 Posted January 6, 2009 Share Posted January 6, 2009 Yes but glazing goes away after a couple hard hits from the pads. Exactly, but it will come back with the appropriate technique, which may be kuryakin's 'normal' mode of brake application. The cheapest fix to try is to go through one of the performance pad maker's bedding techniques and see if this gets rid of the chatter. This will remove most glaze finishes, at least for a short while. I performed a quick stop on the expressway one time with a former vehicle and the brakes went from smooth to a severe chatter by the time I hit about 20mph from my previous 70mph pace. I thought I had warped my front rotors at the time. I decided to try using the Eradispeed bedding technique and it removed the chatter, without having to do anything else, confirming the glazing suspicion. No guarantee it will work all the time, but it is worth a try for free. Link to comment Share on other sites More sharing options...
kuryakin Posted January 6, 2009 Author Share Posted January 6, 2009 Don't think its deposits. I'll check for runout. The rotor surfaces are EXTREMELY clean of anything. I don't drive it hard most of the time, usually long highway drives, but, of course, it IS a GT, so, I have fun from time to time. I've cleaned the rotors with Scotchbrite pads, and it made no difference whatsoever. Hence my question... My guess is I will find warped rotors. If that is the case, who makes the most warp resistant rotors for these cars? Exactly, but it will come back with the appropriate technique, which may be kuryakin's 'normal' mode of brake application. The cheapest fix to try is to go through one of the performance pad maker's bedding techniques and see if this gets rid of the chatter. This will remove most glaze finishes, at least for a short while. I performed a quick stop on the expressway one time with a former vehicle and the brakes went from smooth to a severe chatter by the time I hit about 20mph from my previous 70mph pace. I thought I had warped my front rotors at the time. I decided to try using the Eradispeed bedding technique and it removed the chatter, without having to do anything else, confirming the glazing suspicion. No guarantee it will work all the time, but it is worth a try for free. Link to comment Share on other sites More sharing options...
kuryakin Posted January 6, 2009 Author Share Posted January 6, 2009 And, by the way, the problem was fixed for nearly 10,000 miles, and now it's slowly getting worse... Exactly, but it will come back with the appropriate technique, which may be kuryakin's 'normal' mode of brake application. The cheapest fix to try is to go through one of the performance pad maker's bedding techniques and see if this gets rid of the chatter. This will remove most glaze finishes, at least for a short while. I performed a quick stop on the expressway one time with a former vehicle and the brakes went from smooth to a severe chatter by the time I hit about 20mph from my previous 70mph pace. I thought I had warped my front rotors at the time. I decided to try using the Eradispeed bedding technique and it removed the chatter, without having to do anything else, confirming the glazing suspicion. No guarantee it will work all the time, but it is worth a try for free. Link to comment Share on other sites More sharing options...
05GT Guru Posted January 6, 2009 Share Posted January 6, 2009 I dont know man, i hear good things about DBA and my racingbrake slotted rotors havent had the slightest bit of chatter in the 10kmiles i have been using them. Link to comment Share on other sites More sharing options...
SeeeeeYa Posted January 6, 2009 Share Posted January 6, 2009 Don't think its deposits. I'll check for runout. The rotor surfaces are EXTREMELY clean of anything. I don't drive it hard most of the time, usually long highway drives, but, of course, it IS a GT, so, I have fun from time to time. I've cleaned the rotors with Scotchbrite pads, and it made no difference whatsoever. Hence my question... My guess is I will find warped rotors. If that is the case, who makes the most warp resistant rotors for these cars? You already own a car with the most warp resistant rotors for it, on it. That said, if you go get some new ones or some super whompadyne ones and put some on and find, as you would expect, no warped rotor syndrome, you'll say, "ah ha! I was right! It WAS warped rotors!" Not necessarily so. I'm going to be another one to say it isn't warped rotors. I drove mine hard enough to toast the stock brake pads and turn everything orange when I ran the Tail of the Dragon. Plenty of others have given these rotors even greater 'abuse.' They are big and strong and unlikely to ever simply warp. There is one thing that can cause simple non-vented rotors to warp, improper torque on the lugnuts. It is important to always tighten them in the proper sequence, the proper procedure, and using a torque wrench. Do it wrong and a 'normal' non-ventillated disk may warp. I do the same to every car, regardless of brake system. One cannot just drive disc braked cars, months and years on end, without attending to rebedding the pads. Unless you periodically rebed your pads you will get all the indications you have "warped rotors." Take the offered advice to learn how, and perform a rebedding of your pads. My suggestion is to buy some new pads and perform the correct bedding process, along with a replacement of your brake fluid. Periodically, in a place I know is safe, I get up to about 100mph and brake hard enough to slow the car VERY firmly but without locking them up. I do this about two or three times within a few minutes. Then I drive for a few miles to let the disks cool. Afterward I am rewarded by like new performance without a murmur from the brakes. Link to comment Share on other sites More sharing options...
05GT Guru Posted January 6, 2009 Share Posted January 6, 2009 All these guys are saying the rotors are soo impossible to warp, well guess what i warped the shit outta mine. After i took them off i went around with a mircometer and yes they were warped. I have never tracked my car and 70-80% of my driving was with my daughter in the car and i wasnt doing any spirited driving with her in the car. Link to comment Share on other sites More sharing options...
SeeeeeYa Posted January 6, 2009 Share Posted January 6, 2009 All these guys are saying the rotors are soo impossible to warp, well guess what i warped the shit outta mine. After i took them off i went around with a mircometer and yes they were warped. I have never tracked my car and 70-80% of my driving was with my daughter in the car and i wasnt doing any spirited driving with her in the car. Not to question your assertion, guru, but I personally don't know how one goes about determining warpage of rotors with a micrometer. Link to comment Share on other sites More sharing options...
05GT Guru Posted January 6, 2009 Share Posted January 6, 2009 I just went around the rotors taking measurements about 5-6 on each rotor. Then you can see the difference between each point and if the difference is a good amount you know they are warped. Alot of shops and mechanic friends i have use a micrometer to measure rotors, alot of the time too see f the can be refinished, or where they are most warped or even if they are good to use anymore. I have also used dial indicators but i dont own one so sometimes i just make due Link to comment Share on other sites More sharing options...
SeeeeeYa Posted January 6, 2009 Share Posted January 6, 2009 I just went around the rotors taking measurements about 5-6 on each rotor. Then you can see the difference between each point and if the difference is a good amount you know they are warped. Alot of shops and mechanic friends i have use a micrometer to measure rotors, alot of the time too see f the can be refinished, or where they are most warped or even if they are good to use anymore. I have also used dial indicators but i dont own one so sometimes i just make due Usually a micrometer is used to determine only disk thickness, not warpage. Thickness addresses another issue entirely. Further, uneven thicknesses are often the result of neglect in periodic rebedding, when pad material is unevenly deposited leading to uneven wear. It "feels" like a warped disk, but it ain't . Warping Warping is often caused by excessive heat. When the disc's friction area is at a substantially higher temperature than the inner portion (hat) the thermal expansion of the friction area is greater than the inner portion and warping occurs. This can be minimized by using "floating" rotors which decouple the friction area from the inner portion and allow thermal expansion to occur at different rates. Primary causes of overheating include undersized or overmachined brake discs, excessive braking (racing, descending hills/mountains), "riding" the brakes, or a "stuck" brake pad (pad touches disc at all times). Measuring warping is accomplished using a dial indicator on a fixed rigid base, with the tip perpendicular to the brake rotor's face. It is typically measured about 1/2" (12mm) from the outside diameter of the rotor. The rotor is spun. The difference between minimum and maximum value on the dial is called lateral runout. Typical hub/rotor assembly runout specifications for passenger vehicles are around 0.0020" or 50.8 microns. Runout can be caused either by deformation of the disc itself or by runout in the underlying wheel hub face or by contamination between the rotor surface and the underlying hub mounting surface. Determining the root cause of the indicator displacement (lateral runout) requires disassembly of the rotor from the hub. Rotor face runout due to hub face runout or contamination will typically have a period of 1 minimum and 1 maximum per revolution of the brake rotor. From here: http://en.wikipedia.org/wiki/Disc_brake Here is an excellent read on brakes: http://legacygt.com/forums/showthread.php?t=58401 Link to comment Share on other sites More sharing options...
05GT Guru Posted January 6, 2009 Share Posted January 6, 2009 Like i said in the last post i use dial indicators when i have one available. So basically what i did with the micrometer is spin the rotor but instead of the pin cosntantly touching the rotor i took multiple measurements since a micrometer cant be used like a dial indicator. But when you see that all the points you measured are off eachother you can tell that the rotor is warped. Im at work and dont have time to read a full write up, maybe when i get home. Link to comment Share on other sites More sharing options...
praedet Posted January 6, 2009 Share Posted January 6, 2009 You do realize that warping would not show up in changing thicknesses of the overall rotor, right? That would be pad deposits... If you wanted to check for "warped" rotors you have to check to see if they are true or not. The problem is that deposits will show up in a test like that too... Sorry for you pad deposits, but they are not warped... I take that back, you might have gotten to Grey iron's melting point of roughly 2282 degrees F... Link to comment Share on other sites More sharing options...
05GT Guru Posted January 6, 2009 Share Posted January 6, 2009 So you just said that you would have to test if they are true warped or not. So how do you test for this if not with a dial indicator or micrometer. Then you said even doing the right test that it would still just show up as pad deposit, so how do you test for warping without mistaking it for pad deposit? So in your thinking there is no such things as warped rotors just pad deposit? Its kinda hard to take what your saying serously when you dont explain anything. Such as how your theory is right and how you would do a true test to see if they are warped. Then you end it with sorry for your pad deposits but they are not warped, like you wre there or actually know what your talking about. So if i got pad deposits after 10kmiles of changing the pads then why dont i have them now with my new pads and rotors which i have had for quite a while. Driving to the same places and same style? LOL warping of the rotor doesnt just come from you hitting irons melting point, that comment right there just shows your just talking out your ass. If thats what it took you gettign your rotor to 2200 degrees then no rotors would warp, and the phrase warped rotors wouldnt even be around Link to comment Share on other sites More sharing options...
praedet Posted January 6, 2009 Share Posted January 6, 2009 You are right, you just need to get within 25% of the melting point, atleast w/ Grey Iron Oh, and you are also right, I am actually making this up as I type Link to comment Share on other sites More sharing options...
05GT Guru Posted January 6, 2009 Share Posted January 6, 2009 Im not saying that all im asking you to do is explain how you would truely test for warped rotors since pad deposit seems to get in the way of all rotor testing right? Thats what you said, please explain something. ;) So basically you said its impossible for rotors to warp. good to know Link to comment Share on other sites More sharing options...
SeeeeeYa Posted January 6, 2009 Share Posted January 6, 2009 Speaking of "gurus," I believe these guys qualify: http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml And this is their input, excerpted, complete at above link: <H2>Myth # 1 – BRAKE JUDDER AND VIBRATION IS CAUSED BY DISCS THAT HAVE BEEN WARPED FROM EXESSIVE HEAT The term "warped brake disc" has been in common use in motor racing for decades. When a driver reports a vibration under hard braking, inexperienced crews, after checking for (and not finding) cracks often attribute the vibration to "warped discs". They then measure the disc thickness in various places, find significant variation and the diagnosis is cast in stone. When disc brakes for high performance cars arrived on the scene we began to hear of "warped brake discs" on road going cars, with the same analyses and diagnoses. Typically, the discs are resurfaced to cure the problem and, equally typically, after a relatively short time the roughness or vibration comes back. Brake roughness has caused a significant number of cars to be bought back by their manufacturers under the "lemon laws". This has been going on for decades now - and, like most things that we have cast in stone, the diagnoses are wrong. With one qualifier, presuming that the hub and wheel flange are flat and in good condition and that the wheel bolts or hat mounting hardware is in good condition, installed correctly and tightened uniformly and in the correct order to the recommended torque specification, 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. 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. In order to understand what is happening here, we will briefly investigate the nature of the stopping power of the disc brake system. </H2> Link to comment Share on other sites More sharing options...
praedet Posted January 6, 2009 Share Posted January 6, 2009 ^^^Won't be enough... I have posted that over and over Measure the rotor thickness from inside the vane to the outside (not the entire rotor), starting at the hub, and work out. The areas where pad deposits can't effect measurements are the areas where the pad doesn't contact... If you have greater than factory specified variation in run-out in these areas, you have warping and not pad deposits... Link to comment Share on other sites More sharing options...
SeeeeeYa Posted January 6, 2009 Share Posted January 6, 2009 http://www.goenglish.com/GoEnglish_com_BeatADeadHorse.gif Link to comment Share on other sites More sharing options...
05GT Guru Posted January 6, 2009 Share Posted January 6, 2009 Ic what you are saying, and its not like i was just telling you you were wrong for no reason. You didnt explain anything, all i wanted was an explanation. So in your red text the shelby guys say the havent ever seen a warp rotor, well what about rotors that have a wave effect to them. That causes pulsing in the pedal that is a warped rotor, i have seen these rotor and i have reground rotors since i was 17 and stopped when i was 18 because it doesnt do shit for more than 1kmiles. Then 1 post down he describes what a warped rotor really is, so one of you says there are no warped rotors and the other says there is? Not even you too are agreeing Link to comment Share on other sites More sharing options...
praedet Posted January 6, 2009 Share Posted January 6, 2009 They won't be warped, I was just posting how to test for it Modern rotors on modern cars (when the rotor doesn't come warped from a manufacturor China ) don't warp... Link to comment Share on other sites More sharing options...
ehsnils Posted January 7, 2009 Share Posted January 7, 2009 I suspect that they can warp, but only under special circumstances. Just overheating isn't enough, but if you combine it with uneven cooling you may end up with warped discs. But as noted - there are other causes too - like uneven thickness, built up residue and also caliper malfunction that may cause problems similar to warping. I suffered from corroded caliper suspension with floating calipers and that caused problems since only the outer side of the disc got sufficient pressure applied while the inner got almost nothing. Result - Not good for brake performance. Link to comment Share on other sites More sharing options...
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