Brake rotors warp easily....
- Thread starter RoadRat
- Start date
Register to hide this ad
midnight runner
New member
Rotors aren't the issue. It's the pads giving the "warped" rotor feeling.
When pads heat up they transfer material to the face of the rotor. Once you come to a stop with hot brakes, the pads will imprint more material on one place on the rotor. This is easier to do as pads wear down. Since they are thinner, they don't have as much heat capacity, and they get hotter, transferring material more easily.
The solution? pick up some higher temperature rated pads, or something more intended for truck use. This can still happen, just not as easily.
When pads heat up they transfer material to the face of the rotor. Once you come to a stop with hot brakes, the pads will imprint more material on one place on the rotor. This is easier to do as pads wear down. Since they are thinner, they don't have as much heat capacity, and they get hotter, transferring material more easily.
The solution? pick up some higher temperature rated pads, or something more intended for truck use. This can still happen, just not as easily.
inscarguy
Member
never in my life have i heard that. pads are a softer compound than rotors so they will eventually conform to the rotor. if the rotor is warped or gouged the pad will conform to it. the only way a pad could be warped is if the clip holding it in is broken or there is some foreign substance between the pad and the caliper piston not letting the pad sit flush with the piston. in my opinion pads do not warp if there is nothing wrong with the rotor.
i have too encountered the 4th gen rotors warp. my pads are like new but thanks to my GF(who is able to warp rotors in every vehicle we have owned) warped these rotors on my '06. the problem with any of these new style rotors are that the are "hubless" rotors which means they are the rotors only, no bearings or hub are part of the rotor. in the old days the hub and bearings are part of the rotor and those style rotors took alot more heat and abuse due to them being able to transfer heat better unlike the rotors of today.
either send them out to be cut(if they are within spec) or live with the pulsation until its time for pads.
midnight runner
New member
I haven't heard of warped pads either. I'll clarify. When you get that warped rotor feeling, the rotor isn't really warped. It's excess pad material that has deposited on one extra spot of the rotor. This is often called uneven pad deposition. It's very often diagnosed as warped rotors because the fix is the same. Put the rotors on a lathe to true them out and the problem is solved. Well because the rotors are turned, and it solved the problem, it's often diagnosed as warped rotors.
What I'm saying is pads, and the pad material that gets transfered onto the rotor is what is causing the "warped" rotor sensation.
Check this out for something more indepth.
StopTech : Balanced Brake Upgrades
12guns
New member
I agree w/ midnight runner on this one. Until recently I didn't realize that could happen but after going through 6-8 sets of rotors on my old Tacoma, I'm certian that was the issue. I used to buy the cheapest lifetime warantee pads I could get. That was when I was younger and a broke college student. (I know better broke than dead) Now that I'm older, I run higher quality pads that don't leave the "residue" behind on the rotors.
Example. My 05' Sport V8 had a brake job w/ new OEM rotors and pads. It was SMOOTH as silk for the first 10k miles. Even when really breaking hard on mountian roads. Then I pulled a 5000 lb ski boat w/ no trailer brakes. Immediatly after towing the boat is when I noticed the "pulsing" when I braked. If you'll notice, it feels much more lithe rotors are stickier in certian spots, rather than a mechanical/phisical bend in the rotor face. Anyway, I know there's other opinions but again, I'll go w/ Midnight Runner here, makes the most sense to me. I'll be getting a higher quality pad and rotor for the future so I won't have this issue anymore.
Google "brake juddering" and you'll find a lot of info on this topic. Also you can google "new brake pad break in" and there's some ideas on how to keep the pad from building up on the rotor.
Example. My 05' Sport V8 had a brake job w/ new OEM rotors and pads. It was SMOOTH as silk for the first 10k miles. Even when really breaking hard on mountian roads. Then I pulled a 5000 lb ski boat w/ no trailer brakes. Immediatly after towing the boat is when I noticed the "pulsing" when I braked. If you'll notice, it feels much more lithe rotors are stickier in certian spots, rather than a mechanical/phisical bend in the rotor face. Anyway, I know there's other opinions but again, I'll go w/ Midnight Runner here, makes the most sense to me. I'll be getting a higher quality pad and rotor for the future so I won't have this issue anymore.
Google "brake juddering" and you'll find a lot of info on this topic. Also you can google "new brake pad break in" and there's some ideas on how to keep the pad from building up on the rotor.
midnight runner
New member
I do the StopTech street performance pads, but they have a fair amount of dust. They have really good bite, and high temp range. These might wear the rotors faster than most pads, but that usually translate into less pad deposits as well.
On my 3rd gen I had the Extended wear pads. Those had a little more bite than stock, and more temp range. The only iffy part about the extended wear pads was the 1st stop in the morning like they needed one stop to warm up. After that, they were great.
Toyota 4Runner Products: StopTech big brake kits, stainless steel braided brake lines, brake pads, tires
On my 3rd gen I had the Extended wear pads. Those had a little more bite than stock, and more temp range. The only iffy part about the extended wear pads was the 1st stop in the morning like they needed one stop to warm up. After that, they were great.
Toyota 4Runner Products: StopTech big brake kits, stainless steel braided brake lines, brake pads, tires
137k on mine... I think the OEM rotors are not as "beefy" as aftermarket. I went with Centric rotors on the front and they went much longer w/o needing to be turned as the OEMs, they also felt heavier and of better quality. Recently replaced my rears with Centric as well. The tech's at my shop were impressed with the Centric rotors.
I'd have gone with Brembo, but they don't make rotors (all around) that fit on the smaller diameter 4Runners. (I have the '03 with 17" wheels, but the smaller rotors.)
I'd have gone with Brembo, but they don't make rotors (all around) that fit on the smaller diameter 4Runners. (I have the '03 with 17" wheels, but the smaller rotors.)
oblivionis
New member
The rotors on mine are warped too. I just purchased Centric rotors and EBC Greenstuff pads. We'll see if that stops the problem from reoccurring. (I'm also replacing the calipers because the driver side was really hard to push back when I was changing pads last year).
FourEyedWilly
New member
Uh... I've never run across a rotor that was thicker than new? I've also never heard this before. I dunno but I have been wrong before so is this true?
midnight runner
New member
I've never run across a rotor that was thicker than new? I've also never heard this before. I dunno but I have been wrong before so is this true?
I'm not sure I understand your question. When pads are thinner, there's less pad material to absorb heat, so the pad temps go higher, and imprint easier.
The material that is deposited on the rotor doesn't make it thicker. At least not by any significant measurement.
On the other hand, there are shady super cheap aftermarket companies suppliers that produce rotors with larger airgaps, which means thinner disc friction walls. That equals to a lighter rotor with less heat capacity.
heat management is king when it comes to brakes.
mom
Banned
As stated above, rotors (almost) never warp.
The first step in solving a problem is understanding the problem.
To understand what causes most of what people erroneously think is "warpage", just read the references posted in this thread.
As stated above, most cases of what people "think" is warp, is uneven friction pad deposits.
I had a low speed squeal develop last week. By loosening all the lug nuts and re-torqueing to spec the sound dissipated. My solution sure beat stomping on the pedal trying to get the pad to 'act' correctly.
Whenever you go to a mechanic ask him what the torque specs are and if they don't know, over time you've got only yourself to blame.
Whenever you go to a mechanic ask him what the torque specs are and if they don't know, over time you've got only yourself to blame.
Oh boy, here we go again...
Yes, it is true that what most people perceive as warped rotors is actually uneven pad material deposition on the surface of the rotor. This causes excessive lateral runout and results in a pulsating brake pedal as the pads move in and out over the uneven surface of the rotor.
Some people understand this and others have never heard of it. Either way, the issue at hand is that the pulsation is caused by the movement of the pads over the surface of the rotor. So who really cares if the cause is warped metal or uneven pad material being deposited on the rotor? The end result is the same--the driver feels the pulsation in the brake pedal.
The only real advantage to understanding this problem is to learn how to avoid it in the first place. The best advice I can give anyone is to try not to sit in one place with your foot firmly on the brakes after coming to a hard stop when your brakes were cool. A good example is driving on the highway for many miles and then braking hard down a long offramp and coming to a complete stop at the end. Your brakes would go from cool (with all that highway driving) to very hot (as you braked hard on the offramp) and then you stop at the end of the ramp and your hot pads and rotors are now in contact at just one spot on the rotor. This is one main way for those uneven deposits to occur.
Yes, it is true that what most people perceive as warped rotors is actually uneven pad material deposition on the surface of the rotor. This causes excessive lateral runout and results in a pulsating brake pedal as the pads move in and out over the uneven surface of the rotor.
Some people understand this and others have never heard of it. Either way, the issue at hand is that the pulsation is caused by the movement of the pads over the surface of the rotor. So who really cares if the cause is warped metal or uneven pad material being deposited on the rotor? The end result is the same--the driver feels the pulsation in the brake pedal.
The only real advantage to understanding this problem is to learn how to avoid it in the first place. The best advice I can give anyone is to try not to sit in one place with your foot firmly on the brakes after coming to a hard stop when your brakes were cool. A good example is driving on the highway for many miles and then braking hard down a long offramp and coming to a complete stop at the end. Your brakes would go from cool (with all that highway driving) to very hot (as you braked hard on the offramp) and then you stop at the end of the ramp and your hot pads and rotors are now in contact at just one spot on the rotor. This is one main way for those uneven deposits to occur.
mom
Banned
The important word here is "perceive".
- There is something called "warp" (albeit rare)
- It is measurable (with the rotors on or off the car)
- But you CAN NOT distinguish between warp & other causes of lateral runout while the rotors are on the vehicle
NOTE: I think that's a true statement ... please let me know if it's not.
+1
Those who understand this, don't use "warp" as the term for something that is decided NOT warp (which, see above, is measurable and has NOTHING to do with uneven pad deposition deposits.
Those who do NOT understand this, use the word "warp" thinking that the rotors are deformed (exaggerated, think potato chip).
I doubt many reliable people would use the term "warp" to mean pad deposition because warp exists and is NOT uneven pad deposition.
It's like calling a tire a "wheel". Those who know the answer know that a wheel isn't a tire and vice versa; those who don't have a clue, don't have a clue and often use the wrong term.
It matters when you're trying to UNDERSTAND the reason for your brake pedal pulsation. Anyone who thinks properly torqued brake rotors actually warp in normal usage is already starting off on the wrong DIAGNOSTIC foot (because you have to solve the problem with a change in braking habits among other things).
You care if you're trying to SOLVE a problem.
- First you UNDERSTAND the problem
- Then you repair the problem (i.e., rebed or turn the rotors)
- Then you PREVENT the problem from re-occurring (i.e., you might change your braking habits to prevent the problem from re-occurring and you'd certainly properly bed your rotors since braking depends partially on breaking covalent bonds).
+1
Yup. My point exactly.
You can't solve it and prevent it from re-occurring unless you actually know what is causing the problem (and it isn't warp!).
The important word here is "perceive".
- There is something called "warp" (albeit rare)
- It is measurable (with the rotors on or off the car)
- But you CAN NOT distinguish between warp & other causes of lateral runout while the rotors are on the vehicle
NOTE: I think that's a true statement ... please let me know if it's not.
Those who understand this, don't use "warp" as the term for something that is decided NOT warp (which, see above, is measurable and has NOTHING to do with uneven pad deposition deposits.
Those who do NOT understand this, use the word "warp" thinking that the rotors are deformed (exaggerated, think potato chip).
I doubt many reliable people would use the term "warp" to mean pad deposition because warp exists and is NOT uneven pad deposition.
It's like calling a tire a "wheel". Those who know the answer know that a wheel isn't a tire and vice versa; those who don't have a clue, don't have a clue and often use the wrong term.
It matters when you're trying to UNDERSTAND the reason for your brake pedal pulsation. Anyone who thinks properly torqued brake rotors actually warp in normal usage is already starting off on the wrong DIAGNOSTIC foot (because you have to solve the problem with a change in braking habits among other things).
You care if you're trying to SOLVE a problem.
- First you UNDERSTAND the problem
- Then you repair the problem (i.e., rebed or turn the rotors)
- Then you PREVENT the problem from re-occurring (i.e., you might change your braking habits to prevent the problem from re-occurring and you'd certainly properly bed your rotors since braking depends partially on breaking covalent bonds).
+1
Yup. My point exactly.
You can't solve it and prevent it from re-occurring unless you actually know what is causing the problem (and it isn't warp!).
See, there's where I think you're wrong. No matter what caused the excessive runout, there are really only two ways to correct it. 1-buy and install new rotors or 2- repair the old rotors. Now the only way to truly repair excessive lateral runout is to machine the rotors until they are true again (or within the allowable spec, which is usually 0.002 - 0.004).
So if those are your options, then you have to realize that people will always do one of those two things. And for the most part, they won't care as long as it's fixed....and they won't change their driving habits either. It's not really a complicated problem with a lot of solutions. People like you may care, but most people just want it fixed and they they forget about it.
