I just looked out the window…. its flat. ;-)

 

Yep time to move on .

 

only in Canada . They are still arguing about the vaccine

 

same on here all they ever talk about is battery's , they even thought that a simple change of oil in the supercharged unit in the 5l car was impossible . But they know best

 

hmmm... I think you'll find the 'crazies' are everywhere.
I've always maintained 90% of the population doesn't qualify for the privilege to vote...
And not wanting to embarrass, infuriate, or discriminate against any particular group, I'll just leave it at that.

 

Any way dudes im out of here . just like some managed to **** of a very good and knowledgeable poster by the name of Q&C i shall leave you to the hounds of Iowa or desert flats or god forbid the boring sons off Canada , wonder why Canada gets that name

 

Finally.....and speaking of warp

 

Exactly, somehow this seems lost in the semantics of this (as CeeJay so points out). Back in the day when I had cheaper cars and bargain basement parts I would get shudder on braking, have the rotors turned for minimal cost, and problem was resolved usually the remainder of the time I had on the car. Sometime a resurface is required to resolve the buildup or other reason induced surface warpage.

I just wish I could get a frying pan made out of the magical metal that Rotors are made from, my expensive large chef frying pan warped like a **** (yes the manufacturer replaced for free with lifetime warranty). Seems like an easy fix for the pan manufacturers, follow what the Rotor people do and no more expensive replacements.

 

Sounds like a 'definition' argument and not really a 'myth' argument.

Yes, always check your battery condition when they tell you your brakes are bad...

 

Front rotors are always two flat sheets of cast iron with a fin structure in between creating all these box like structures. They arent flat pieces of thin metal like a frying pan. So front rotors are pretty stout and in order for a bending to occur, you need to deform those small box like structures. Its not easy. And sure they can bend if you get into an accident and kiss something solid with the rotor. But heat? It would have to get pretty damn hot and I think youd end up melt the or destroying the pads, boil out out the fluid and melt the seals in the caliper.

I used to think rotors warped until I read about the pad material transferring to the disk. The pad material makes the rotor friction vary so you are sticky in some places and slippery in others. So when you hit the brakes you get a pulsation as the friction changes cause the rotor to slip and stick. Its easy to convince yourself that the rotor is warped.

I learned the truth when I attempted to re-bed pulsating brakes by hammering on the brakes repeatedly to remove the pad material from the rotor. It works every time.

all you need to do is try it and convince yourself. It works

btw even if the rotor was installed at an angle, you would feel that without applying the brakes as the tilted portion rub on one pad then the other as it rotated. So youd feel that pretty easily and your pads would disappear in short order

 

You'll be sorry when you step on your brakes and your headlights go out.

 

Why does everyone keep saying that you cannot generate enough heat to warp a rotor, that is a given!!! What warps most metal isn't heat, unless you toss them in a furnace. It is when they get hot and then (say here in Florida) you hit water and they are exposed to rapid cooling. And so forth. Rapid heat rapid cool can affect metal of any type, everybody wants to quote science but ignores this simple fact.

To say anything is impossible to me is much too absolute of an answer, to say it is unlikely or rare, that I can get on board with and agree that pad imprint is probably the most common issue.

 

I'm already sorry for having an electronic handbrake...

 

Great article...

 

I reckon everyone here's just going to have to agree to disagree as there're some quite strong beliefs as to the definition of what it takes to warp cast iron brake rotors. There are numerous car expert sites which confirm what I and others have stated, that "warped" in reference to brake rotor's a misnomer. I ran this discussion by a friend who's been a mechanic for over 35 years and he said in all those years and thousands of brake jobs later, he's yet to see "warped" brake rotors. Those of you who wish to disagree with science, expert experience or empirical data, well then there's no likely hood of changing your mind regardless of anything.

 

Thanks all - this thread was a welcome relief from reading work emails! Can't tell you how many times, growing up, my parents took the family car into the dealership for the replacement of "warped rotors"... my dad drove his cars hard, but I am guessing it was not warped rotors but pad material being unequally spread across the face of the rotor. As a long-time bicycle mechanic, I always took care to bed new pads onto rotors, and can now apply this to cars (though bike rotors do in fact warp under continuous heavy load, but they are easy to straighten without taking off the wheel... no breaker bar or torque wrench needed!).

 

I just wish I could learn how to stop the random squeaks and squeals. Off-brand, but not off-topic, I've redone my vintage Corvettes brakes over and over and over again, rebuilt, replaced and rebuilt every component on all four corners multiple times over the past decade and finally given up. It'll absolutely throw out the anchor, but its just gonna squeal or chirp at random and drive me crazy. I'll be rolling into the car show and then as I line up very slowly into a position, it'll make a light squeal from any random corner. Or I'll drive through the neighborhood and hear a very light chirp, chirp, chirp that stops as soon as I touch the pedal even the slightest. But if I have somebody else drive it while I run along side to listen for which wheel either of these noises is coming from, no, it won't make a sound. I've had other cars with brake noises that were equally as frustrating. For me, its always noises that I hear at speeds anywhere from inching along up to maybe 10 or 15mph. Stopping from any faster and the brakes are always quiet. I've bought a couple of "how to fix your brake" type books at Half Price but I have yet to find one that describes what each kind of brake noise actually means and how to fix it. Books always describe noises in general and then how to take it apart and put back together again.

The article posted was very interesting but does anyone know of a great book about how to identify the subtle differences between break system noises (an audio book would be awesome) and diagnose them or is that kind of information considered "insider information" that the worlds best retired brake system mechanics have sworn to take to their grave with them?

 

The BMW 635 can experience a shuddering of the front suspension under braking which someone could easily mistake for a warped disc. In reality what the car needs is new trailing arm bushings. So many weird things out there could mimic what seems to be warping. Of course an astute BMW owner might notice that there’s no feedback through the brake pedal, but how many of “today’s” drivers qualify as astute?

 

Wait... 0100110 DOES = 38! (26 hex)

So many years ago I had a ‘74 Satellite. I did a brake job, even had the rotors turned, but one of the pistons froze up and caused the rotor to really warp. Fixing the caliper and turning the rotor again fixed the problem for about a week. Then it was again bad. So the moral of this story is, yeah, rotors can warp. But it’s not common.

The other thing I learned is that it’s not always good to have the rotors resurfaced, or “turned”. One of the problems is that it removes material, makes them thinner, and shortens their service life. The other drawback is that the metal “work-hardens” and that puts a hard layer on the surface of the disk, and that helps it last longer. So my rule of thumb is if the disk looks good and smooth, just leave it alone and replace the pads. If looks uneven or badly scored (like if you didn’t replace the pads in time), don’t even waste the time of having the disk resurfaced. Replace it with a new one.

Just my dos centavos.

 

Phil,
On my pre-Jag cars I often got random brake squeak and squeal much like you describe and after trying all sorts of things I finally found a once and for all fix - CRC DeSqueak, see here https://www.ebay.com/itm/27480616513...wAAOSw539gqFBj
I bit of a pain to use as you have to thoroughly coat both sides of each disc/rotor then bed it in (just like bedding in a new set of rotors and pads) but it really works, after using it I never had a hint of squeal or squeak again.