My Honda (an Acura TL) came stock with 4 piston Brembos and huge vented rotors. However if you didn’t buy the manual transmission you got some really shitty brakes! I guess they figured if you bought the automatic you wouldn’t be driving it hard. The only time they warped was when a tire shop didn’t torque the lugs correctly.
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.
I've found that most parts suppliers offer several different levels of quality for passenger car rotors. Buying the better quality ones has worked out well for me. Pads too. I was surprised to learn that the hub can easily warp.
Excellent video. Even I, a person with minimal mechanical education, were able to understand everything. Thank you, I now know what to ask for and what to say to my mechanic when he tells me my car needs new rotors.
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.
Interesting. Yeah, it would be hard to test bedded vs non bedded brakes. I didn't get into the possibility of turning the rotors. I think the general thought is now that they are from China it's cheaper to just buy new ones. Wasteful for sure.
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.
Re-machining out of parallel rotors is a sellable service because it does not solve the problem long term. It simply removes material until it is parallel again. The problem with machining out of parallel rotors is that you introduce thickness variation in the planes that upon further use will encourage the return of the prior symptom with an increasing interval until the rotor is no longer within machining tolerances and requires discard. The shop can sell you a cheap fix for right now and they know they can sell it again and again ultimately ending in the replacement of the rotor. If the rotor is out of parallel, then replace it and correct the conditions that caused it to become out of parallel in the first place. Even if that requires training the operator how to use the vehicle properly.
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.
I purchased a Honda S2000 new in 2003. I have driven it at Sears Point Raceway a dozen times. I literally 'Stand' on the brake pedal from 110-112 mph braking for turn 11. I still have the S2k. It currently has 34,000 miles on the odometer. I have replaced the front rotors twice. I never had any problem with vibrations or pulsating with the pedal or steering wheel, although the last set of front rotors I replaced were heavily cracked. I have always driven hard in the S2k
For race applications the Rotor is only the friction surface. The Rotor is attached to the Hat via "flexible" fixings. This is known as a "floating" disc. Road applications have the Rotor and Hat as one piece. These installations are known as floating calibers (hence the slide pins).
Been doing the break in procedure since my first rotor change, because it was written in the instructions coming with the parts. Thickness variation on a street car, is a thing mostly caused by axial runout. The axial runout lead to the pads touching the rotor at only 2 points when not braking. These contacts will thin the rotor around them in around 10 000 to 20 000 km. Thickness variations will cause the dreaded pulsations. There are many less frequents causes but axial runout is the number one. The runout can be in the wheelhub not nescessarilly the rotors. A cheap dial indicator on a stand will pick it up.
@@MikeTheBackyardMechanic The recommended procedure is to check the run-out on the hub before installing the discs. I did that on the third pair of discs changed under warranty one week before expiry, on my wife car. One day before expiry of said warranty I collected the car and checked the axial runout with a dial. Then drove it back to the garage before closing to show them. Then it was : " Remember attack the mistake not the man." "Stay calm" " Only state what you can prove" Had them(liability issue could not do it) remove the wheel check the disc run-out Which was off, then remove the discs and check the hub's run-out which was off as expected. Took the bus back home while they waited for a new hub. When the hub is back you will be throwing discs for a temporary fix. This is expensive, I can not understand why they did not do it on the second disc change.
Warped rotors are caused by improperly and unevenly torqued lug nuts. As little as a 5 lb ft difference between two lug nuts on the same wheel will cause a warped rotor when the car is driven hard. When you get on the brakes hard at say 170 mph for a corner those things get cherry red and then cool off quickly from having 100 mph air going through them. If there is any uneven torque on them they will warp. The same condition can affect a vehicle, towing a heavy trailer in the mountains. Tire shops tend to install tires with an impact gun with torque sticks. This practice has cost me a couple very expensive sets of rotors! If anyone touches your lugs make sure to loosen and re torque them yourself with a good and recently calibrated torque wrench ASAP.
Watching your video as my 2018 Kia Soul gets it's rotors and pads replaced AGAIN for the second time in less than a year. The rotors were warped before and are warped again. It's pretty frustrating. And I'm not a crazy driver. While I do maybe to deal with a lot of stop and go traffic to and from work, I've only had this vehicle for a little over 18 months. My three previous vehicles, an old Honda Fit, a Dodge Avenger, and a Dodge Caravan never experienced any issues with brakes like this. I had the same commute to work with those vehicles.
You most likely have hub runout. If runout is over .002 inches it causes uneven friction material build up on the rotor high spot. New rotors will feel fine then start pulsating again after 1-2 years. Demand who ever is servicing the car to check hub runout and if over .001 to correct it with hub/rotor shims. All shops know how to do this but prefer installing new rotors and pads every 1-2 years.
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.
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.
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 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
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.
I can relate. Discount Tire put the wheels on my Mustang and I estimate they were torqued to 250 lbs. It took me 45 minutes, a long breaker pipe, and much sweat to loosen them.
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
That makes complete sense. I was in a hurry to finish this brake job, or I would have ran the indicator over the new rotors. But obviously The Thump is gone.
I just had this happen to my rotors on my pilot. There was a pool of backed up water from the rain in the garage in my building as i ran thru it my brakes started steaming and now have the " thump" as he would call it
Yep, we have a 2nd gen Pilot too. The front rotors are junk. 20k is about all we get yet the pads never show much wear. The rears were still pretty good at 90k.
Also use a good, high quality brake caliper grease such as ''Permatex Synthetic Brake Lubricant'',, Expensive YES but worth it! I also put a bit of blue loctite on the caliper mount bolts and the caliper bolts (not the slides) I have seen a caliper just ''fall'' off a car at 35mph, (NOT from my work!)
I find those little rubber thingies on slide pins to be a problem. They make the slide pins stick. Ive tried cutting them to shorten but have switched to eliminating them. Any feedback is appreciated on your experience
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.
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.
Rotors always seemed to have a common problem with "warpage". We changed tyres on a Mitsubishi Outlander once and later wondered why the front shudder suddenly appeared (annoyingly). But later when tried to change a flat tyre (in the dark at airport) -discovered the stud nuts were near impossible to remove!!! In the latter days of asbestos brake shoes (and pads) my dad taught me to always bed the new brakes in, but whether that was to avoid damage to the pads or match the surfaces is debatable. - ps. Rattle guns should be outlawed for final wheel nut tensioning!
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 👍
I'm from Detroit and worked on many, many rusted cars. I know the feeling! I wouldn't be able to twist the brake line 360º and it still fit, so I don't THINK I twisted it. But now you have me second guessing myself.
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.
Interesting that EV brake rotors rust! I don't know about different crystal sizes - you saw the measurements on the rotor. Regardless, I may take you up on the intermediate measurement. I bought pretty cheap rotors, and they are already bumping a bit. Tolerable. I like your idea to get them turned and see if they are relaxed.
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
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.
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.
That's interesting. I'm pretty sure it was the driver's side that went bad on the Pilot as well (the video cuts between both sides, but I think the indicator reading was on the river's)
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.
Im about to lose it. Machined the rotors three times on my 2012 Pilot and they still pulsate. Only 1 thou runout on the hub flange. Can anyone recommend a quality set of rotors?
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.
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 like your take on bedding brakes. Our house is 5 miles from the freeway and 2 miles from a main road. Perhaps they warp on long trips (where most of the miles happen on this car) when it's raining. But it shouldn't happen. The first two sets of rotors were middle range O'Reilly's. The last set was inexpensive R1 Concepts. I don't expect them to last a year. The next set might be DBAs or similar, but it will be at least 2 1/2 years before we know the results. Buying a premium rotor is a lot like buying a premium mattress. You don't really have any idea what you are getting or how long it will last.
@@MikeTheBackyardMechanic It really does come down to the metallurgy of the rotor. I've learned over the years that Raybestos "Service Grade" is going to teach you to be skillful at replacing components. Also had horrible return rates with Centric lower and mid-tier offerings. On a Honda I would tend to advise my service writer to offer the customer either a Bosch cryo-treated rotor or a mid-tier Akebono rotor to minimize how often we would see warranty service. I'm certain there are other options of equal or better quality if you are bold enough to experiment. We don't have that luxury in the shop though.
I can't find any Bosch cryos. StopTech cryos are $170 each (yikes). Akebono performance are available for only slightly more than I paid for the R1 Concepts.
These used to be O'Reilly rotors. The ones I put on were R1 Concepts. Because of the price, I don't expect them to last longer. But the next set I may splurge.
Isn't disk thickness variation what you just showed us as warping? Or is this funny funny man saying because the backside also followed the same pattern it would be called warping? Warping due to heat imbalances, disk thickness variation due to what?
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.
@@iamtheoffenderofall, The cars are heavier and the motors (in general ) produce more torque, so it make sense that the tires wear faster. But with regenerative braking the pads engage the rotor far less frequently. Thus there will be less wear on the pads and the rotor won't heat up as much. Can you please explain how and why brakes on an EV with regenerative braking would wear faster than an ICE powered vehicle?
I did the research. EV brakes typically last much longer. HOWEVER @drkgumby, if you use the poor brake habits of stopping hard in wet weather, you may have to deal with warped rotors. Assuming they are as shitty as Honda's.
@@MikeTheBackyardMechanic perhaps. But i think it would need a more extensive experiment to concure. In my opinion, disc rotors do warp, when heated & cooled (drastically at a short period of time) this goes back to the materials built used in the rortors, is it able to sustain such heat, maintain its composition when cooled. Etc We haven't seen rotors made of the hardest materials yet. Id like to give a suggestion to it, titanium
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.
Perhaps, but so are warped rotors. It sounds like we each have scenarios that lead to our problems. These warped rotors (or just the one anyway) were from O'Reilly's, and cost $130 each. Crazy expensive. The ones in the video are cheap R1 Concepts, and seem to already be thumping. I'll goo with higher quality next time. Which might be soon.
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."
Get rid of the music while you're trying to explain something
Music is my weakness. Still trying to dial it in.
you nailed it ... Honda rotors are undersized.... they do not take much heat...
My Honda (an Acura TL) came stock with 4 piston Brembos and huge vented rotors. However if you didn’t buy the manual transmission you got some really shitty brakes! I guess they figured if you bought the automatic you wouldn’t be driving it hard. The only time they warped was when a tire shop didn’t torque the lugs correctly.
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.
I've found that most parts suppliers offer several different levels of quality for passenger car rotors. Buying the better quality ones has worked out well for me. Pads too. I was surprised to learn that the hub can easily warp.
Excellent video. Even I, a person with minimal mechanical education, were able to understand everything. Thank you, I now know what to ask for and what to say to my mechanic when he tells me my car needs new rotors.
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.
Interesting. Yeah, it would be hard to test bedded vs non bedded brakes.
I didn't get into the possibility of turning the rotors. I think the general thought is now that they are from China it's cheaper to just buy new ones. Wasteful for sure.
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.
Re-machining out of parallel rotors is a sellable service because it does not solve the problem long term. It simply removes material until it is parallel again. The problem with machining out of parallel rotors is that you introduce thickness variation in the planes that upon further use will encourage the return of the prior symptom with an increasing interval until the rotor is no longer within machining tolerances and requires discard. The shop can sell you a cheap fix for right now and they know they can sell it again and again ultimately ending in the replacement of the rotor. If the rotor is out of parallel, then replace it and correct the conditions that caused it to become out of parallel in the first place. Even if that requires training the operator how to use the vehicle properly.
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.
I confess I went with the flow on torque being a cause of warped rotors. I mostly advocate for torquing lugs so that the wheels stay tight.
I purchased a Honda S2000 new in 2003. I have driven it at Sears Point Raceway a dozen times. I literally 'Stand' on the brake pedal from 110-112 mph braking for turn 11. I still have the S2k. It currently has 34,000 miles on the odometer. I have replaced the front rotors twice. I never had any problem with vibrations or pulsating with the pedal or steering wheel, although the last set of front rotors I replaced were heavily cracked.
I have always driven hard in the S2k
For race applications the Rotor is only the friction surface. The Rotor is attached to the Hat via "flexible" fixings. This is known as a "floating" disc. Road applications have the Rotor and Hat as one piece. These installations are known as floating calibers (hence the slide pins).
Wow, eye opening. This information was like anti-seize for my brain.
LOL!
Been doing the break in procedure since my first rotor change, because it was written in the instructions coming with the parts.
Thickness variation on a street car, is a thing mostly caused by axial runout.
The axial runout lead to the pads touching the rotor at only 2 points when not braking.
These contacts will thin the rotor around them in around 10 000 to 20 000 km.
Thickness variations will cause the dreaded pulsations.
There are many less frequents causes but axial runout is the number one. The runout can be in the wheelhub not nescessarilly the rotors. A cheap dial indicator on a stand will pick it up.
A dial indicator is a good idea. I should make a video.
@@MikeTheBackyardMechanic The recommended procedure is to check the run-out on the hub before installing the discs.
I did that on the third pair of discs changed under warranty one week before expiry, on my wife car. One day before expiry of said warranty I collected the car and checked the axial runout with a dial. Then drove it back to the garage before closing to show them. Then it was : " Remember attack the mistake not the man." "Stay calm" " Only state what you can prove"
Had them(liability issue could not do it) remove the wheel check the disc run-out Which was off, then remove the discs and check the hub's run-out which was off as expected.
Took the bus back home while they waited for a new hub.
When the hub is back you will be throwing discs for a temporary fix. This is expensive, I can not understand why they did not do it on the second disc change.
Very informative and hilarious, I was ROTFL more than once. The furball doesn't seem to care. It's sleeping time.
Warped rotors are caused by improperly and unevenly torqued lug nuts. As little as a 5 lb ft difference between two lug nuts on the same wheel will cause a warped rotor when the car is driven hard. When you get on the brakes hard at say 170 mph for a corner those things get cherry red and then cool off quickly from having 100 mph air going through them. If there is any uneven torque on them they will warp. The same condition can affect a vehicle, towing a heavy trailer in the mountains. Tire shops tend to install tires with an impact gun with torque sticks. This practice has cost me a couple very expensive sets of rotors! If anyone touches your lugs make sure to loosen and re torque them yourself with a good and recently calibrated torque wrench ASAP.
BS
Watching your video as my 2018 Kia Soul gets it's rotors and pads replaced AGAIN for the second time in less than a year. The rotors were warped before and are warped again. It's pretty frustrating. And I'm not a crazy driver. While I do maybe to deal with a lot of stop and go traffic to and from work, I've only had this vehicle for a little over 18 months. My three previous vehicles, an old Honda Fit, a Dodge Avenger, and a Dodge Caravan never experienced any issues with brakes like this. I had the same commute to work with those vehicles.
You most likely have hub runout. If runout is over .002 inches it causes uneven friction material build up on the rotor high spot. New rotors will feel fine then start pulsating again after 1-2 years. Demand who ever is servicing the car to check hub runout and if over .001 to correct it with hub/rotor shims. All shops know how to do this but prefer installing new rotors and pads every 1-2 years.
@@Reloadeez Thank you for that!!
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.
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.
I'll have to pay attention, the next time the rotors go bad and look back at the weather (still, they shouldn't do that).
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.
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 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
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.
I can relate. Discount Tire put the wheels on my Mustang and I estimate they were torqued to 250 lbs. It took me 45 minutes, a long breaker pipe, and much sweat to loosen them.
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
That makes complete sense.
I was in a hurry to finish this brake job, or I would have ran the indicator over the new rotors. But obviously The Thump is gone.
I just had this happen to my rotors on my pilot. There was a pool of backed up water from the rain in the garage in my building as i ran thru it my brakes started steaming and now have the " thump" as he would call it
Yep, we have a 2nd gen Pilot too. The front rotors are junk. 20k is about all we get yet the pads never show much wear. The rears were still pretty good at 90k.
I'm going to try expensive rotors next. I was told cryo's work.
@@MikeTheBackyardMechanic Frozen Rotors? Just googled and looks promising.
Can you get front-end vibration from a warped rotor without breaking
Also use a good, high quality brake caliper grease such as ''Permatex Synthetic Brake Lubricant'',, Expensive YES but worth it! I also put a bit of blue loctite on the caliper mount bolts and the caliper bolts (not the slides) I have seen a caliper just ''fall'' off a car at 35mph, (NOT from my work!)
I find those little rubber thingies on slide pins to be a problem. They make the slide pins stick. Ive tried cutting them to shorten but have switched to eliminating them. Any feedback is appreciated on your experience
Nice troll
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.
So you're an advocate for cryo treated rotors, eh? I wasn't sure if that was voodoo or not.
No voodoo, it does really work. I found out about it when I worked for a factory Porsche racing team that ran 24 hr races in the early 2000s.
NEW information is telling his WIFE he put used rotors on the kitchen counter tops ..get the banket and pillow ready for the couch. !!!
HAHAHAHAHA!! When I do these longer videos, sometimes jokes get left on the table. Or in the bed.
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.
Porsche recommends anti seize on their lugs, but to also increase the torque 10%. The extra torque is needed for the decrease thread friction.
Rotors always seemed to have a common problem with "warpage". We changed tyres on a Mitsubishi Outlander once and later wondered why the front shudder suddenly appeared (annoyingly). But later when tried to change a flat tyre (in the dark at airport) -discovered the stud nuts were near impossible to remove!!! In the latter days of asbestos brake shoes (and pads) my dad taught me to always bed the new brakes in, but whether that was to avoid damage to the pads or match the surfaces is debatable. - ps. Rattle guns should be outlawed for final wheel nut tensioning!
No such thing as warped rotors
Very informative video. If I had a mechanic like you in my city...just take my money!
HAHAHA! Thanks
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 👍
I'm from Detroit and worked on many, many rusted cars. I know the feeling!
I wouldn't be able to twist the brake line 360º and it still fit, so I don't THINK I twisted it. But now you have me second guessing myself.
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.
Interesting that EV brake rotors rust! I don't know about different crystal sizes - you saw the measurements on the rotor. Regardless, I may take you up on the intermediate measurement. I bought pretty cheap rotors, and they are already bumping a bit. Tolerable.
I like your idea to get them turned and see if they are relaxed.
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
He mentions that in the video.
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.
Bedding brakes is time consuming. I would assume 0 do it.
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.
That's interesting. I'm pretty sure it was the driver's side that went bad on the Pilot as well (the video cuts between both sides, but I think the indicator reading was on the river's)
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.
If you didn't watch the video I hope you at least liked it 👍
Im about to lose it. Machined the rotors three times on my 2012 Pilot and they still pulsate. Only 1 thou runout on the hub flange. Can anyone recommend a quality set of rotors?
I've heard only the cryos will work. I may just swap out cheap rotors every 6 months.
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.
Love your analogy! It might be in a future video!
Rotors don't warp.
In my experience it is not warpage that couses brake shake. It is thickness variation.
So blue spots? Or another term for warpage?
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 like your take on bedding brakes.
Our house is 5 miles from the freeway and 2 miles from a main road. Perhaps they warp on long trips (where most of the miles happen on this car) when it's raining. But it shouldn't happen.
The first two sets of rotors were middle range O'Reilly's. The last set was inexpensive R1 Concepts. I don't expect them to last a year. The next set might be DBAs or similar, but it will be at least 2 1/2 years before we know the results.
Buying a premium rotor is a lot like buying a premium mattress. You don't really have any idea what you are getting or how long it will last.
@@MikeTheBackyardMechanic It really does come down to the metallurgy of the rotor. I've learned over the years that Raybestos "Service Grade" is going to teach you to be skillful at replacing components. Also had horrible return rates with Centric lower and mid-tier offerings. On a Honda I would tend to advise my service writer to offer the customer either a Bosch cryo-treated rotor or a mid-tier Akebono rotor to minimize how often we would see warranty service. I'm certain there are other options of equal or better quality if you are bold enough to experiment. We don't have that luxury in the shop though.
I can't find any Bosch cryos. StopTech cryos are $170 each (yikes). Akebono performance are available for only slightly more than I paid for the R1 Concepts.
Dude, I appreciate your science!
Sticks?
Most of the time, it is locked brake pad on one side.
I think I would notice if the car would only make right turns.
When in bed you should have turned the pad so you could "spoon".
Funny how we had different interpretations of which way the pad faced would be sexiest.
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.
These used to be O'Reilly rotors. The ones I put on were R1 Concepts. Because of the price, I don't expect them to last longer. But the next set I may splurge.
Rotors are cast.
Isn't disk thickness variation what you just showed us as warping? Or is this funny funny man saying because the backside also followed the same pattern it would be called warping? Warping due to heat imbalances, disk thickness variation due to what?
Disk thickness variation is high spots or ack of parallelism.
Stop pointing out the facts , you will wreck everything !……. 😜😆
Speed +heat in friction brakes=warped rotor, like balanced tires, not a myrh⁉️🤑🙏🔥🔫☠
He’s a cat dude, now I like him.
How about just sticking with the car stuff.
Sounds like you don't like my comedy channel.
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.
Actual real world facts disprove that statement. Brakes and tires wear out faster on EVs over ICE vehicles
@@iamtheoffenderofall, The cars are heavier and the motors (in general ) produce more torque, so it make sense that the tires wear faster.
But with regenerative braking the pads engage the rotor far less frequently. Thus there will be less wear on the pads and the rotor won't heat up as much. Can you please explain how and why brakes on an EV with regenerative braking would wear faster than an ICE powered vehicle?
@@drkgumby you're so woefully ignorant on the subject that i urge you to actually research the topic.
I did the research. EV brakes typically last much longer. HOWEVER @drkgumby, if you use the poor brake habits of stopping hard in wet weather, you may have to deal with warped rotors. Assuming they are as shitty as Honda's.
@@iamtheoffenderofall Perhaps that is true. Would you be kind enough to point me to some of your sources?
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 !
Here. New info that disc rotor does wrap!: th-cam.com/video/B6UM4P1c8mA/w-d-xo.htmlfeature=shared
I saw that in my research. This is what I do to the Pilot. Do you think it might be the problem?
@@MikeTheBackyardMechanic perhaps. But i think it would need a more extensive experiment to concure. In my opinion, disc rotors do warp, when heated & cooled (drastically at a short period of time) this goes back to the materials built used in the rortors, is it able to sustain such heat, maintain its composition when cooled. Etc
We haven't seen rotors made of the hardest materials yet. Id like to give a suggestion to it, titanium
Nice shirt !!!
Dunna nuna nuna nuna nuna BATMAN
Edit- you said 'hard on", hehehehehehehe
Belatedly: heh... hehehheh... heh...
not enough nunas
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.
Perhaps, but so are warped rotors.
It sounds like we each have scenarios that lead to our problems.
These warped rotors (or just the one anyway) were from O'Reilly's, and cost $130 each. Crazy expensive. The ones in the video are cheap R1 Concepts, and seem to already be thumping. I'll goo with higher quality next time. Which might be soon.
I absolutely abhor alliteration!
But I passionately prefer penning prose in this particular pattern!
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
I take requests.
@@MikeTheBackyardMechanic [Insert obligatory Freebird! request here]
😆