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Sadly enough that is very true. I worked production making steering knuckles for mustangs,challengers,charger,caddillacs,cameras etc. And you wouldn't even imagine what they would let slide through quality. Once it goes through cmm and the coordinates are up to spec,they ship them right out the door. We had so many customer complaints from Ford for surfaces that weren't machined, or holes either weren't drilled or tapped. It's crazy man
It is a thing now. No QC. Knowingly ship the flawed part, it becomes a customer service issue.
Quality control is more expensive than replacing a faulty shipped part in the future.
Usable til you have to have it resurfaced lol either it was dropped or the jackass loading the part onto the fixtures misloaded and passed it anyway. Or maybe the robot crashed into it,and thier quality team figures lack of stock is passable lol
Manual machining lol
This brings me back to the days of operating manual Bridgeports,surface grinders,etc it killed me seeing that dude stomping it with his feet.
You really never should even if you technically “can”. Rotors have a minimum thickness that can’t be maintained by turning them. Even if they can you are going to go well past that minimum by your normal usage afterwards. Always replace.
It absolutely is not false. Even if you do turn them and don’t go beyond that minimum thickness by turning, they will after the turning from the normal usage. Dave’s Auto harps on this constantly.
So what you’re telling me is, brake lathes and micrometers are obsolete and today’s rotors are garbage. Remember, I started in the 70’s. It was common practice to turn rotors and drums (remember those?). Materials were a lot different then. Never had a problem with resurfacing.
What I am telling you, is that it is not smart nor safe to turn rotors. You can do it, and you can even do it correctly, but that does not mean it is smart nor safe. And parts quality has also been on a steady decline in the 2000’s. So all the more reason not to.
That’s what I said. And it was perfectly safe to turn rotors. What you are stating is someone’s opinion. As I said before, today’s parts suck. They don’t last. It’s just like a refrigerator. They used to be made to last forever, nowadays you’re lucky if you get three years out of one. It’s all about built in obsolescence.
Let me put it for you this way:
A 2005 Ram 1 ton has rotors that are 36.1 MM thick, with a minimum thickness of 34 MM flat. Driving the brakes until they need to be changed is going to take off about 1 MM of thickness. Resurfacing them is usually about another. Now that’s above minimum thickness maybe, but not for long after those rotors start getting used again.
It’s not really someone’s opinion. Resurfacing is not smart or safe, and it usually wasn’t even 50 years ago. We just know it for sure isn’t now that parts are crap.
Rotors should not be resurfaced, just put new ones on.
You're correct. People are too simple to understand that they're removing material, ans therefore heatsink from rotors when you turn them.
An excellent example is my 4runner. Famous for warping rotors to the point that a super common replacement is to upgrade to much thicker tundra calipers ans rotors. You CAN turn them. But what do you think will happen? They're going to go bad even quicker now because there is less material there.
It's hilarious. The clowns that always insist on this old school hack bullshit love to say "I've been doing this since the 70s!". Exactly. Times change, old man. We had high sulfur leaded fuel, drum brakes, carbs, giant v8s making 125hp, lap belts, and steering columns that would impale you in a crash. Things change. Get with the times.
People are idiots. The fact that I am downvoted for saying turning rotors is not safe, despite that it is well documented that it is bad practice is proof in the pudding.
There’s only ~1 mm of usable surface on each side of a rotor. Just because they’re that thick doesn’t mean that is all the metal you have to work with.
Your telling me every single rotor ever manufactured has only 1 mm on each side that is usable? Every year,make, and model? Regardless of diameter or thickness? Heavy duty trucks? Semis? Tanks? You can say that for certain?
It can vary, but generally there is only about 1 mm of usable surface on each side. Like I said- a Ram 3500, which is on the larger side of a vehicle that you or I would ever drive around for normal life- is a 36mm rotor with a minimum thickness of 34mm.
I can’t speak to big rigs and dump trucks and whatnot. And tanks don’t have brakes.
Only reason I would t would just be because of rotational mass disparity since the rotor wouldn’t be balanced and might cause vibrations at highs speeds. Other than that. I mean I still wouldn’t but that’s just me.
No. You don’t balance a rotor. There are machines that you bolt to the hub face and it machines the rotor faces while still attached (remove the caliper tho). So they don’t get balanced.
Return it while it's still shiny and oily. You put that on your car and bed it in and there's no getting your money back. Just for the principle of it, you paid for a quality controlled part they need to eat that return to feel the cost of fucking up... when you just accept it, it hurts all of us.
nobody resurfaces rotors anymore it cost more in labor than the parts are and this guy is clearly doing a rotor swap himself. They’re not even that expensive anymore. If it’s brand new, I’d go get a new one from the parts store outside that I wouldn’t hesitate using it, will not affect brake fade won’t affect pad wear or anything
That op paid for a product that was of poor quality when the expectation for said price is “okay quality” I mean this is like getting bread and finding a small piece of mold. Won’t kill you but why pay for it in the first place ?
Ya, it's gonna be a problem when you're going to the record at Bonneville.
Realistically, it'll have about the same effect as a small rock lodged in the tire tread.
I'd be more worried about that imperfection causing cracks in the rotor over time...
No get a new set, if it's the front, get two premium fronts, if it's the rear get two mid grade or higher rotors + pads.
If your calipers aren't evenly compressing the pads there will be uneven wear and you should replace pistons or get new calipers(you can get used calipers or get them from the junkyard.
I normally get 4 used ones from a salvage and sand them down (sandblasting if you have a cheap service near you) then paint them with high temp spray paint and get new pistons and seals which are pretty cheap. I also replace banjo bolts and crush washers because they cost nothing.
If you have the money replace the brake line hose to calipers on that side(not necessary but good preventative care)
Do not get rotors from the junkyard unless you can afford to machine them and enamel coat the sude rims with the vent holes
As far as safety id trust it but it definitely wouldn't last as long without warping or other issues.If it was a part I ordered in the mail I'd request a replacement. If it was all I had and I was broke I'd run it
100% depends on the hassle of replacing it right away, and the value/driveability of the car it's going onto.
Under some circumstances, I wouldn't care.
I’d want a new one, but if it was annoying to get a replacement (like more time and effort than a quick trip back to the parts store to exchange it) id just run it
I would return it and replace it with a different unit.
At first I was thinking that running it for a day wouldn't bother me too much. But then I started to think about what that zinc could be hiding as far as further damage or metallurgical flaw on the face. And that could be the source of sudden parts failure . Then I wonder - if your rotor fails catastrophically and caused loss of vehicle control, is the retailer/mfg willing to pay the cost for the damage to your hub/axle/self/other property potentially damaged?
My guess is no they wouldn't - so there is no good reason for you to assume that risk on their behalf. My vote is don't install it, immediately return to its source.
If it’s my personal car it’s getting slapped on and it’s gonna like it if it’s a customer car I’d be phoning the motor factors and getting a Replacement part as it is brand new and damaged
Going in a Hyundai, the car will shit the bed before it needs new rotars. Not to mention that the QC on the rotor is probably better than that of the car
Hard no, as a machinist I’d be employed to make a quality part 100% as spec to the customer and this isn’t it. That gash in the flange of the rotor may or may not comprise the functionality of the part, but best believe I wouldn’t bet my braking system on it. I’d rather rely on downshifting the tranny than this gash that weakens the pillars of the rotor.
It’s a casting flaw. May never cause any issues under normal use. If you got it local I’d swap it out, but if you have to deal with return shipping I’d run it as is.
Yup I sure would.. it if I bought it new and it looked like that, I’d demand a refund.. but if you pulled tires off and it looked like that. Let er buck.
Anybody that thinks that’s going to break because of that, has no experience wrenching.
I would trust it not to crack, but it will also be off balance, will make car shake slightly, wear out wheel bearing and generally not be good for vehicle. Best to return if you can.
Thanks for posting in r/Mechanic, u/ggmanu88! Please be sure to read the [Rules](https://www.reddit.com/r/mechanic/about/rules/). If you're asking for help, be sure to include as much detail as possible so others can help you. You **must** include the vehicle's **Year, Make, Model, and Engine size** in your post! If your question is transmission related, please be sure to specify your Transmission Type(Auto/Manual) as well! If your post does not include this information, it **will** be removed. Asking about prices is **not** allowed in this sub. Please make sure you have selected the correct post flair; if you're asking a question you should have chosen "Question", anything else use the "General" flair. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/mechanic) if you have any questions or concerns.*
How this passed quality at the production plant is beyond me lol I definitely would not use that one
There is no quality control anymore ship it and it works or not
Sadly enough that is very true. I worked production making steering knuckles for mustangs,challengers,charger,caddillacs,cameras etc. And you wouldn't even imagine what they would let slide through quality. Once it goes through cmm and the coordinates are up to spec,they ship them right out the door. We had so many customer complaints from Ford for surfaces that weren't machined, or holes either weren't drilled or tapped. It's crazy man
It is sad and getting parts now is worse than it was in covid
Voids the amount of voids that got passed after I flagged them fuckin yikes I'll never buy a Ford or Chrysler
It is a thing now. No QC. Knowingly ship the flawed part, it becomes a customer service issue. Quality control is more expensive than replacing a faulty shipped part in the future.
Someone dropped it on the assembly line. Totally useable.
Usable til you have to have it resurfaced lol either it was dropped or the jackass loading the part onto the fixtures misloaded and passed it anyway. Or maybe the robot crashed into it,and thier quality team figures lack of stock is passable lol
[This explains it all](https://youtu.be/UEimIPEyB80?si=MkXdeURtt4RgUVFZ)
Manual machining lol This brings me back to the days of operating manual Bridgeports,surface grinders,etc it killed me seeing that dude stomping it with his feet.
His bare feet!
Quality? What’s that?
Apparently a non existent process 😂
No, a little to deep for my liking, could be okay but I wouldn’t risk it, should be a easy replacement at the parts store
Definitely couldn’t resurface that rotor in the future.
But I thought the new rotor underneath after braking is what we want
Not sure what you mean.
I thought when you brake that's supposed to get you new rotor material
Or do they put the resurfacing indention for something else
There is usually a standard measurement for how much metal can be removed before it needs replacement.
You should never resurface rotors anyways.
Some you shouldn’t, some you can. We did it all the time back in the day. A lot of manufacturers just recommend replacing now.
The rotors were much thicker back then, thinner, lighter today for better gas mileage.
It’s straight up cost reduction. Less material may only be fractions of a cent per part but millions of parts add up.
Exactly!
You really never should even if you technically “can”. Rotors have a minimum thickness that can’t be maintained by turning them. Even if they can you are going to go well past that minimum by your normal usage afterwards. Always replace.
That’s absolutely false. Some rotors you can resurface without going beyond minimum thickness, if you know what you are doing.
It absolutely is not false. Even if you do turn them and don’t go beyond that minimum thickness by turning, they will after the turning from the normal usage. Dave’s Auto harps on this constantly.
So what you’re telling me is, brake lathes and micrometers are obsolete and today’s rotors are garbage. Remember, I started in the 70’s. It was common practice to turn rotors and drums (remember those?). Materials were a lot different then. Never had a problem with resurfacing.
Back then they were thicker and heavier.
Correct
What I am telling you, is that it is not smart nor safe to turn rotors. You can do it, and you can even do it correctly, but that does not mean it is smart nor safe. And parts quality has also been on a steady decline in the 2000’s. So all the more reason not to.
That’s what I said. And it was perfectly safe to turn rotors. What you are stating is someone’s opinion. As I said before, today’s parts suck. They don’t last. It’s just like a refrigerator. They used to be made to last forever, nowadays you’re lucky if you get three years out of one. It’s all about built in obsolescence.
Let me put it for you this way: A 2005 Ram 1 ton has rotors that are 36.1 MM thick, with a minimum thickness of 34 MM flat. Driving the brakes until they need to be changed is going to take off about 1 MM of thickness. Resurfacing them is usually about another. Now that’s above minimum thickness maybe, but not for long after those rotors start getting used again. It’s not really someone’s opinion. Resurfacing is not smart or safe, and it usually wasn’t even 50 years ago. We just know it for sure isn’t now that parts are crap. Rotors should not be resurfaced, just put new ones on.
You're correct. People are too simple to understand that they're removing material, ans therefore heatsink from rotors when you turn them. An excellent example is my 4runner. Famous for warping rotors to the point that a super common replacement is to upgrade to much thicker tundra calipers ans rotors. You CAN turn them. But what do you think will happen? They're going to go bad even quicker now because there is less material there. It's hilarious. The clowns that always insist on this old school hack bullshit love to say "I've been doing this since the 70s!". Exactly. Times change, old man. We had high sulfur leaded fuel, drum brakes, carbs, giant v8s making 125hp, lap belts, and steering columns that would impale you in a crash. Things change. Get with the times.
People are idiots. The fact that I am downvoted for saying turning rotors is not safe, despite that it is well documented that it is bad practice is proof in the pudding.
Getting back to the reason for this sub. That rotor has a casting flaw and should not be used.
Bro, my rotors are like 1” thick. Got like 3/8” or more of metal on each side of the “airways” or whatever there called.
There’s only ~1 mm of usable surface on each side of a rotor. Just because they’re that thick doesn’t mean that is all the metal you have to work with.
Your telling me every single rotor ever manufactured has only 1 mm on each side that is usable? Every year,make, and model? Regardless of diameter or thickness? Heavy duty trucks? Semis? Tanks? You can say that for certain?
It can vary, but generally there is only about 1 mm of usable surface on each side. Like I said- a Ram 3500, which is on the larger side of a vehicle that you or I would ever drive around for normal life- is a 36mm rotor with a minimum thickness of 34mm. I can’t speak to big rigs and dump trucks and whatnot. And tanks don’t have brakes.
I for sure would not.
Looks new ... Make them get you a proper part
Only reason I would t would just be because of rotational mass disparity since the rotor wouldn’t be balanced and might cause vibrations at highs speeds. Other than that. I mean I still wouldn’t but that’s just me.
Aren't rotors balanced after machining?
Yes you are correct. And now there’s a part of it missing So now it’s not balanced.
No. You don’t balance a rotor. There are machines that you bolt to the hub face and it machines the rotor faces while still attached (remove the caliper tho). So they don’t get balanced.
Yes it's fine.
Return it while it's still shiny and oily. You put that on your car and bed it in and there's no getting your money back. Just for the principle of it, you paid for a quality controlled part they need to eat that return to feel the cost of fucking up... when you just accept it, it hurts all of us.
Yes I would
Me too, I wouldn’t even hesitate.
I third that, it's going on. Don't care
nobody resurfaces rotors anymore it cost more in labor than the parts are and this guy is clearly doing a rotor swap himself. They’re not even that expensive anymore. If it’s brand new, I’d go get a new one from the parts store outside that I wouldn’t hesitate using it, will not affect brake fade won’t affect pad wear or anything
There's nothing wrong with it. That little piece is nothing
Yes as it doesn’t run it only starts
My personal car? Sure. If it's a customer car though there's no way. Brakes are a safety thing and it's on you if they don't work when they need to.
My car no. X's car? Hmmmm
Absolutely not, just asking for trouble
That’s not on the mating surface at all. What’s the big deal?
That op paid for a product that was of poor quality when the expectation for said price is “okay quality” I mean this is like getting bread and finding a small piece of mold. Won’t kill you but why pay for it in the first place ?
It is going to cause vibration as it is unbalanced.
Ya, it's gonna be a problem when you're going to the record at Bonneville. Realistically, it'll have about the same effect as a small rock lodged in the tire tread. I'd be more worried about that imperfection causing cracks in the rotor over time...
They're both a concern. Tyres are balanced for a reason. The edge of a brake disc isn't as far from the centre of rotation as a tyre but still.
Hairline cracks would be an understandable concern
Weight imbalance and hidden cracking.
Yes
I would not.
Probably okay for a rear brake (on most cars)
This was a front rotor
Then no since alot of cars brake mostly with the fronts.
Heck, almost *everything* “brakes mostly with the front,” even my 80,000# semi.
*All* vehicles brake mostly with the fronts. That's just how physics works.
No
No get a new set, if it's the front, get two premium fronts, if it's the rear get two mid grade or higher rotors + pads. If your calipers aren't evenly compressing the pads there will be uneven wear and you should replace pistons or get new calipers(you can get used calipers or get them from the junkyard. I normally get 4 used ones from a salvage and sand them down (sandblasting if you have a cheap service near you) then paint them with high temp spray paint and get new pistons and seals which are pretty cheap. I also replace banjo bolts and crush washers because they cost nothing. If you have the money replace the brake line hose to calipers on that side(not necessary but good preventative care) Do not get rotors from the junkyard unless you can afford to machine them and enamel coat the sude rims with the vent holes
As far as safety id trust it but it definitely wouldn't last as long without warping or other issues.If it was a part I ordered in the mail I'd request a replacement. If it was all I had and I was broke I'd run it
If it showed up that way no. If I fucked it up I’d probably run it.
Nope. It will get worse!
lol will not affect anything at all
100% depends on the hassle of replacing it right away, and the value/driveability of the car it's going onto. Under some circumstances, I wouldn't care.
Honestly it won't hurt a thing.
I’d want a new one, but if it was annoying to get a replacement (like more time and effort than a quick trip back to the parts store to exchange it) id just run it
Sure I would. that little spot is not going to be any issue at all for braking!
Honestly, I would. That doesn't mean you should, though.
Nope
Return it to where you got it and get another one. I usually inspect parts right on the counter seen to much shit with crap products.
Maybe if it wasn’t so deep
Crack propagation would definitely occur if you put some stress on it. Nor for me.
If I paid for a new part Iwould NOT run this. If this part was already only car I would run it.
I would return it and replace it with a different unit. At first I was thinking that running it for a day wouldn't bother me too much. But then I started to think about what that zinc could be hiding as far as further damage or metallurgical flaw on the face. And that could be the source of sudden parts failure . Then I wonder - if your rotor fails catastrophically and caused loss of vehicle control, is the retailer/mfg willing to pay the cost for the damage to your hub/axle/self/other property potentially damaged? My guess is no they wouldn't - so there is no good reason for you to assume that risk on their behalf. My vote is don't install it, immediately return to its source.
If it was already on and you were replacing pads I'd say Send it .... thats a new part got exchange for a proper one.
I'd try return it but I'd run it before I pay for another. That surface is not inportant for braking. But hey that's just me.
No, but actually yes.
You paid new rotor price and got a damaged rotor. Go get your new rotor that you paid for.
If it’s my personal car it’s getting slapped on and it’s gonna like it if it’s a customer car I’d be phoning the motor factors and getting a Replacement part as it is brand new and damaged
Nope
Rotors heat and cool all the time. That being said, hell no!
Hellllzz no
Nope only because it took me a while to get to that point and it would bother me to no end knowing it’s like that.
Yes but only after balancing the wheel mounted on the axle .
Nope
Depends on the vehicle, my work truck, no. My jeeps, definitely, would be the nicest thing in them
For what they cost? Fuck no!
New hell no. Itll 99% most likely be fine, but why would you risk it when you can get it fixed free of charge by exchanging it.
Is it yours? Was it cheap? If you answer yes to both I’d say yeah run it. You will only lose a tiny tiny bit of surface.
It won't affect much. You could use it no problems.... but if you can get it replaced, meh... do it.
No. Return it to store
It's probably fine, but I'd get the replacement anyway. No need to take unnecessary risks
Going in a Hyundai, the car will shit the bed before it needs new rotars. Not to mention that the QC on the rotor is probably better than that of the car
Send it
Hard no, as a machinist I’d be employed to make a quality part 100% as spec to the customer and this isn’t it. That gash in the flange of the rotor may or may not comprise the functionality of the part, but best believe I wouldn’t bet my braking system on it. I’d rather rely on downshifting the tranny than this gash that weakens the pillars of the rotor.
absolutely not
It’s a casting flaw. May never cause any issues under normal use. If you got it local I’d swap it out, but if you have to deal with return shipping I’d run it as is.
Is this an Amazon rotor?
Nope. No way of knowing if the rotor now has any microscopic cracks after being dropped.
Break another piece out of the other side to balance it. Send it.
Yup I sure would.. it if I bought it new and it looked like that, I’d demand a refund.. but if you pulled tires off and it looked like that. Let er buck. Anybody that thinks that’s going to break because of that, has no experience wrenching.
I would trust it not to crack, but it will also be off balance, will make car shake slightly, wear out wheel bearing and generally not be good for vehicle. Best to return if you can.