Warped Rotors LIES DISPROVED - NEW INFORMATION! 

I've been working on cars since 1968. Yes, I bed brake pads to new rotors, but I can't really say that it makes a hell of a lot of difference. As for rotor warpage, I've measured exactly the same thing that you did in this video, and I've noticed that the rotors which display it most reliably are the ones with the thinnest bridge between the hub and friction surface. And from over 50 years of driving experience, I can say that the most frequent cause I've directly observed is uneven *cooling* of a rotor that has become extra hot. And, sometimes, just getting the rotor too blasted hot will do it regardless, such as has happened on long downgrades in the Rockies and Cascades while running with my Caravan fully loaded. On the original Taurus, Ford infamously had two-piece rotors that were so bad about warping that they changed the design - but not enough to completely eliminate the problem. Want something to show how much more the manufacturers are lying? Check the thickness of a brand new, right-off-the-shelf rotor, and then look at what's stamped on it for a wear limit. It's been years since I found one that wasn't going to be "past limits" after 0.005" of wear on each side, 0.010" total thickness loss. Back in the days when they were still made with enough meat to make resurfacing "safe", we routinely took off more than that. Now, you can't do it with a fresh one. That's utter BS.

you nailed it ... Honda rotors are undersized.... they do not take much heat...

Very informative and hilarious, I was ROTFL more than once. The furball doesn't seem to care. It's sleeping time.

When I replaced my rotors and pads I didn't explicitly go and break them in but I did take five minutes out of my drive to allow for minimal breaking before getting on the highway where I essentially broke them in by slowing down very fast and letting them cool by mostly transmission breaking for a few minutes.

Wow, eye opening. This information was like anti-seize for my brain.

installed new rotors on my yukon xl and got a pulsating pedal , was getting .010" runout on 1 rotor . New rotor had some runout and the bearing hub had some rust and had to be aggressively cleaned with flap wheel. clocked the rotor till I got minimal runout. indicator and a mag base is required. also cutting old rotors properly works great as the stresses even out and stop moving due to many heat cycles. Carol Smith has some great books explaining proper fasteners and and techniques.

NEW information is telling his WIFE he put used rotors on the kitchen counter tops ..get the banket and pillow ready for the couch. !!!

I often "bed the brakes" but just to be sure everything is going to function properly in the wild. Just a couple of times after a few normal stops, I will start at 35mph and stop as hard as possible. Not slamming but quickly depressing the brake pedal until abs or lockup, then release some pressure to come to a normal stop.

Excellent presentation. Enjoyable humor and full of information. Breaking in new pads and drums: I drive a couple miles around 25 mph and lightly tap my brakes every few seconds. I figure this will allow ridges on the disks to begin defining matching grooves in the friction material. Also to clean out bits of manufacturing residue. I don't think your hypothesis about heat in the hubs allowing the molecular structure to relax is correct. Cast iron annealing requires temperatures above 550C (1020F). Now that I drive only cars with regenerative braking, my rotors suffer more from rust than from wear. Perhaps you could measure & record run out on mounted disks, repeat the measurements when you first notice pulsation, and a 3rd time when it becomes intolerable. My suspicion is that there will be no change, and the cause is poor manufacturing caused formation of islands of different crystal sizes with different friction coefficients. Only the most superficial few microns is homogenous. It might also be interesting to have a pulsing disk turned. Having been relaxed, the corrected absolutely planar surface should be maintained if relaxation is the cause.

Hairline cracks in a few of the ribs which are invisible and when cold don't cause pulsations in the pedal. After a few stops the rotor halves will open up and pedal will pulsate. Probably caused by a hard stop and holding the pedal.

I have bedded all my brakes for about the last 15 years and it helps sometimes. If you live in Miami, LA or Phoenix and you stop and go a lot, then bedding your rotors should help. It has for me. BUT, my Hondas warped rotors like crazy no matter what! I torqued the rotors in steps to spec and would actively avoid hitting standing water when I knew my brakes were hot and those helped, but they still warped. My rotor warpage went away when I went to cross-drilled and slotted rotors, and switched to driving Lexus. Let the hate begin......... but seriously, it doesn't cost anything to do 4-5 panic stops from 70mph and see if the pedal quits pulsing. I mean, if it doesn't help, they were warped anyway, right? So I guess my driving habits do make a difference! But for me, I'll just replace my rotors each time I replace my pads as standard practice. they aren't that expensive anyway.

I really enjoy your show I mean it's informative and funny at the same time I wish I could do more of these automotive shows the definitely give yourself a pat on the back excellent

Groves in pads are caused by groves in the rotor… groves in rotor are caused by inferior material… 1-1000 shops bed brakes…because most don’t know why they should.

You can also have a rotor that is slightly warped brand new. I have seen that many times. The biggest problem is that rotors are not as thick anymore and you usually can't turn them because they will be too thin. Usually heavier trucks have thicker rotors and can be turned. Most shops don't turn rotors anymore because it's not very cost effective. Times have changed.

Nice video and you're correct it's usually it's in reference warp rotor has more to do with the hub center not being thick enough as the metal contract backed into a different spot therefore causing the warpage. Oh and you are aware that you can have the rotors turned to correct your issue that applies to both non floating and floating rotors and yes I do use tab bit on anti-seize on the lug nuts and no it does not affect the torque valued one bit not as high as some say I've literally done hundreds of tires, suspension components and everything else in between and just about every vehicle I did that came back it came apart easily not rusted on. Now as for bed brake pads to new rotors there is a purpose part of it has to do with the stuff they put on the rotors to keep them from rusting in the packages no matter how well you clean them there will always be some in the pores of the material also by doing this you crystallize the material which helps metal from rusting sooner it depend on where you live. I was take the vehicle up to 45/50mph and brake hard to 5mph that speed up and do again that I do it.

Very informative video. If I had a mechanic like you in my city...just take my money!

I determined over the decades that the "runout" as described here (Lateral run-out?) is what often causes this thickness variation which is what causes the pulsing pedal. As the rotor wobbles back and forth, it wears down the rotor unevenly as it hits either the inboard or outboard pad in the same spot all the time. This can be caused by bent wheel hubs. Another cause is "rust jacking" between the rotor and the hub. Rust is like water when it freezes--it expands. The force is sufficient to cause enough lateral runout to generate that uneven wear on the rotor as it slides by the pads. Then, you end up with thickness variation which is what causes that pulsing brake pedal. The runout alone doesn't cause the pulsing pedal unless the caliper slide pins are seized, or it is a severe amount of runout. And also, as mentioned in the video, stress spots being relieved via normal heating and cooling cycles. Some of these castings are so poorly made, that it is of no surprise that the hub area is what warps. If you want good brake parts, buy them from the dealer. I also had exceptional luck with "Inroble" branded rotors. They don't rust out nearly like the typical auto parts store ones do. But they are hard to obtain. As for lug nut torque causing this, I call MOSTLY bogus on this one, based on my own tests with a dial indicator and bolting a wheel spacer on to simulate a wheel attached. This was under "no-load" conditions, but I would expect that the irregular lug nut torque would have to differ greatly. I haven't used an actual torque wrench to tighten lug nuts in probably 12 years now. I learned my impact gun and I know what it does.

Dude, I appreciate your science!

I've chucked up brand new rotors on the brake lathe and most of them are "warped" right out of the box. The biggest thing that causes warping after installation is braking and wet weather. The heat cool cycle warps the hub like you were alluding to. Cheers

you might want to look into infrared emissivity to understand EE's video a little better. of course the hottest part of the disc will be the one in contact with the pads, but being "shiny" it reflects infrared light more

I had the same issue with a VW I used to own, I bought a new set machined them to make sure the run out was minimal then had the rotors Cryogenically treated and the issue went away and never had to replace the rotors again.

Uneven bedding is real. Cant speak for statistics vs actual warped rotors. Ive measured the rotors on my jeep cherokee kl with 45k on the oem brakes and it had less than .001" total indicated runout on all rotors. Repeating a bedding procedure did fix it for a while, and its still not as bad as it was. The exit for main highway where i live is on a reasonably steep down hill and ends at a light that is always red. So everyone goes from 65 mph (or 80 but I follow the speed limit of course...) to a complete downhill stop in maybe 500 feet or so then the brakes get held in that spot untill the light is green. Seems like the perfect recipie for uneven pad transfer. I would hate to just replace the pads and rotors with a ton of meat left on them. My hunch is most rotors that truly warp are cheaper aftermarket (or some lower quality oem) that are lower quality.

I never had problems with the brakes on my Ridgeline. My bro in law with a one year newer Ridgeline does repeatedly with pulsating brakes. He also is a two footed driver that rides his brakes and we have hills to make things worse. Coming from a colder wetter climate 50 years ago it was common for stories of people hitting deeper puddles or slush after having heated the brakes and getting pulsating/warped rotors. I always recommend torque wrenches when mounting tires.

When my pedal pulsates, I change the rotor. I don't bother comparing the rotor to my dick thickness. When I replace the brakes, I drive down the street applying the brakes several times at low speed. That has always worked fine for me. Currently, I own a jeep wrangler, 2 Ford trucks, and a Subaru (wife). I am an aircraft mechanic, so I know a thing or three about hot brakes. Car brakes aren't that, and I don't stress over them.

The fricken dealership over torqued my hubs when they insisted on rotating my tires when I went for the oil change. They are refusing to admit it and want to charge me for a new rotor and the warranty deductable for the service. I will do it myself. Dishonest, commission paid @$$holes at Zimmer Dodge in Burlington, Ky.

Brake pads need to be properly bedded in and that rarely happens. What is diagnosed as warped rotors is often deposits of pad material on the rotor. Source: StopTech

One quick critique... when you put the caliper on after the pads, the brake hose seems like its twisted or routed improperly. The hose should have a nice arc to it. Otherwise very good video. I do like the clamp on the pads while putting on clips. Beats holding the pads, installing both clips, and putting caliper on at the same time 👍. Im very jealous though. You must live in a southern or non rust belt state as the hubs and bracket were pretty clean. When I take off rotors I have to use a needle scaler and grind off the rust 😒. Otherwise very good, informative video. First time watching 👍

In my experience it is not warpage that couses brake shake. It is thickness variation.

Don't even have to watch the video. TLDR: No it's not a myth, yes you can over heat rotors and cause them to cool unevenly. This is how cylinder head warpage happens and why you have to turn down rotors, exhaust manifolds, cylinder heads and more.

Warpage is the deviation from center on a parallel surface. DTV is the presence of a swell in a parallel surface. One displays both surfaces moving together out of center and the other displays both faces moving in opposition of each other. DTV is often caused by parking the vehicle with hot rotors. This happens because the cast iron rotor retains the heat under the pads, slowing the rate at which it contracts as it cools. This results in the slowest points becoming squeezed outward as the rest of the rotor contracts. The growth of DTV can be minimized by changing your driving habits to allow the air to cool the rotor before parking the vehicle. Your argument that because you aren't working the brakes to near the point of brake fade means the rotors are not hot is invalid. This can happen with as little as a highway speed stop being within two blocks of your home or work because you applied heat into the rotor with insufficient distance traveled after that stop to properly reduce the rotor temperature. Bedding in rotors is intended to fill voids in the rotor from the machining processes used during the creation of the rotor. As for your outro, if the rotors on the vehicle are "under engineered" then you should have no issue buying a premium rotor to replace them and not see the issue arise again. It seems apparent that you have changed the rotors multiple times without it changing the result on the long term.

I fewl your pain with the honda rotors. I've also noticed on both odysseys that I've owned the driver front rotor always has the most runout. I theorize that the master cylinder is weaker on the right front/left rear circuit, but i don't have the tools to scientifically back that up.

I think it's caused by poor quality steel . I switched to Power Stop brakes and rotors and problem solved ! BTW. Was using auto zone rotors.

When in bed you should have turned the pad so you could "spoon".

He’s a cat dude, now I like him.

Here. New info that disc rotor does wrap!: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-B6UM4P1c8mA.htmlfeature=shared

Yeah rotors warp, and I don't even think it's limited to hub warping (I don't know this) "Rotors don't warp" is aobut as dumb as the recent "don't wash your legs or they're dirtier". I washed my car the other day. I didn't wash the lower half, because according to this recent internet viral videos, anything LOWER should be cleaner if you just let the suds wash over it and not physically wash your legs/lower half. If that's the theory, don't wash your legs or their actually more dirty, why not just put drop of sop on your the highest point of your skull (or back for hunch backs...I don't discriminate) and you should be cleaner from just rinsing the drop of soap off.

Speed +heat in friction brakes=warped rotor, like balanced tires, not a myrh⁉️🤑🙏🔥🔫☠

Nice shirt !!! Dunna nuna nuna nuna nuna BATMAN

in the 70's and 80's it was DADDY went to the store for a pack of smokes !! hi strange man 10 yrs later are you my daddy ? no im just your uncle kid !

Stop pointing out the facts , you will wreck everything !……. 😜😆

I absolutely abhor alliteration!

I have an EV. I use regenerative braking as much as possible. I wonder if my rotors will be less likely to warp because less use means less heat. Or it could be the opposite. In an attempt to save weight and taking regen into account the genius bean counters undersized them. One good Texas summer and two hard stops and they'll be as straight as a politician stumping for reelection.

Actually anti seize on the lug threads will give a more accurate torque on the lug nut because you are removing friction between metal surfaces. When you torque Head bolts you always soak them in motor oil, it's the same principle. Arp head studs come with a special torque lube and it's basically a low friction lube similar to anti seize to make sure the nuts can move freely against the head surface under tension until the desired torque is achieved.

Get rid of the music while you're trying to explain something

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Romans 10:9-11 9That if you confess with your mouth, "Jesus is Lord," and believe in your heart that God raised him from the dead, you will be saved. 10For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved. 11As the Scripture says, "Anyone who trusts in him will never be put to shame."

Bad music