Does anybody know why my 2003 F250 front brakes keep warping? I have replaced the rotors and pads many time but I have yet to see them not warp. I even replaced the calipers about two months ago and they're warping again. I was told it could be the axle bearing but I have no idea. Please help!! Thank you.

 

Long story short, its heat, plain and simple. As to why they warp so bad i cannot say. I went thru the same thing over and over again. I would change to new rotors and pads and as little as two weeks later they would be warped. I would ride it until i couldnt take it any more then change, then 2-3 wks later,here we go again. I was turning/changing rotors/pads every 6 mths.

Then I bought a set cryo frozen and slotted rotors along with Hawk Brake pads. The LTS series pads is what i have on now and that combination is great. Dont get any pad with ceramic in it, the heat build up is too great and will even warp the cryoed rotors, ask me how i know, took 6 mths instead of two weeks but still did it. Like I said, at first i had the wrong rotor/pad combination, but now after getting the right combination, I am going on 2.5 yrs before i noticed any warping again. I put the right parts in Sept. '12 and I just started noticed a bit of warping about 2 mths ago, still light and not bad yet, i plan on turning and putting new pads on again later this month. But that was 80k miles ago after putting these parts on. Beats the hell out of two weeks and only 1000 miles.... I think its a winner. You can read about what i went thru here, lots of good info from the group.

 

Are your brakes releasing all the way when you take your foot off the pedal? I have read repeatedly here that the rubber lines can go bad on the inside and leave the fluid trapped thus causing the brakes to remain stuck on after releasing them.

 

I've been told that rotors don't warp. It's actually more due to glazing causing uneven friction around the rotor making it feel warped. Every front brake problem I've ever had was due to the back brakes not doing their part and causing the front brakes to work harder.

 

"I've been told that rotors don't warp. It's actually more due to glazing causing uneven friction around the rotor making it feel warped."

I have read the same thing. Don't know if that is internet folly or not though. One big cause was making a hard stop and keeping the brakes on a red hot rotor creating a hard spot in it.

 

Have you checked the runout on the rotor to make sure they are in spec?

 

Rotors can warp, but rarely is it the actual reason people have brake pedal shimmy.

Here is some info I've previously posted years ago regarding the warped feeling of rotors caused by the pulsing brake pedal.

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The rotors aren't really warped in the true sense of the word. There are hot spots being created in the metal which causes the formation of Cementite.

"Cast iron is an alloy of iron and silicon in solution interspersed with particles of carbon. At elevated temperatures, inclusions of carbides begin to form in the matrix. In the case of the brake disk, any uneven deposits - standing proud of the disc surface - become hotter than the surrounding metal. Every time that the leading edge of one of the deposits rotates into contact with the pad, the local temperature increases. When this local temperature reaches around 1200 or 1300 degrees F. the cast iron under the deposit begins to transform into cementite (an iron carbide in which three atoms of iron combine with one atom of carbon). Cementite is very hard, very abrasive and is a poor heat sink. If severe use continues the system will enter a self-defeating spiral - the amount and depth of the cementite increases with increasing temperature and so does the brake roughness."
StopTech : Balanced Brake Upgrades

Once hot spots/cementite has formed (aka "black spotting") the rotor is cannot be "cured" of the problem (by turning them) and new rotors are necessary.

I agree that the pads are probably the major factor in causing this problem, but the quality of the rotor plays a big part too.

The problem everyone complains about when they use the term warped rotors, brake shudder, pulsing brakes, etc almost always is not due to a warped rotor.

The definition of warp is a twist or curve that has developed in something originally flat or straight. That's not what's happening to the rotor when it comes to the problems described here. The problem is hot spots or black spotting which is the formation of cementite. No amount of turning on a lathe can eliminate this problem.

Here is another excerpt by Carroll Smith in his article "The 'Warped' Brake Disc and Other Myths of the Braking System"

"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."
StopTech : Balanced Brake Upgrades

There's even information about Cementite found on EBC's web page.

Hot spots, black spotting, cementite, carbite, hard spots, whatever you wanna call it, it cannot be fixed by turning the rotor. These spots are what causes the brake shimmy, pulsation, warped feeling that people complain about in the "warped rotor" threads.

My Ex had this problem back in '05 and I can't remember how many times I had them turned, but it never solved the problem.

How are you torquing your wheels down when you put them back on the truck? Are you using a two-step method or are you just torquing each lug down to spec and then moving to the next lug and repeating the process?

Have you tried measuring the temp of each rotor to see if one is unusually hotter than the other?

Stewart

 

^^^To summarize the previous post...if you press the pedal too hard, the calipers squeeze the magic out of the rotors.

 

Assuming calipers and slide pins are functioning properly - Driving style and pad choice are the primary reasons for warped rotors. Stop using the crap pads they sell at autoparts store and get some good ones. I use and strongly recommend EBC pads. I use the Yellowstuff pads because I tow heavy and live in the mountains. Greenstuff are a little cheaper and may last a little longer while having a little less dust.

I use 'lifetime warranty' rotors and since I started using good pads - I have yet to warp a set. I get 60k+ miles out of a set of pads and usually just trade the rotors in for new ones when I replace the pads.

I have put this set-up on a bunch of PSD's now and everybody is very happy with it.

Good luck and let us know what ya decide!!!!!!