Totally confused about a brake rotor replacement

2 1/2 years ago I purchased a “used” 2004 Hyundai Sonata with only 100 miles on it. The car now has 26,000 miles. I recently took my car in for its annual safety inspection. I was informed that I had approx. 4-6 months left on my brake pads so I should begin thinking about taking the car in for new pads in the near future. About a week later, the brakes began making a grinding noise so I decided to take them to the mechanic right away to have the pads replaced. The mechanic told me I still had wear on the pads, however, the rotors (front and rear) would need to be replaced due to pitting and rusting. Needless to say, I was confused. I questioned how this could be, but the mechanic didn’t have much of a response. I then called the dealership and asked them about it. They stated that I hardly ever drove the car (10,000 miles per year) and that condensation was most likely pitting and rusting the rotors due to the fact that it “sits too much”. I drive in bumper to bumper rush hour traffic every day so I’m on the brakes alot. I have owned many cars in the past and I am NOT heavy on the brakes at all. My other cars rotors have always lasted at least 60,000 miles in the same type of driving conditions.

Does anyone have any idea what could have caused the rotors to be pitted and rusted and yet the pads still have 6 months wear on them? I’m at a loss on this one.

It does not seem quite right to me either. You can get underneath the car to look at the rotors with a mirror and flashlight. You can see some portions of the rotors through the wheels too. Make sure that the swept area of the rotor as much as you can see, has not been reduced due to corrosion. The swept area shoulld be as wide as your brake pads. Go to car parts store to inspect a new pad for your car as a reference; they should be willing to accommodate you; if not find another store where your business might be welcomed.

By the way, there is no rule to prevent you from buying the parts and having a mechanic install them for you.

Normally, a little rust will be polished off with a few brake applications.

If you do get the rotors replaced, then ask for the old parts. This will help to keep your mechanic honest or else get a second opinion. I have doubts that all four must be replaced but anything is possible.

Consider this approach. You may need to replace the rotors, so check and see if your independent mechanic can find the Wagner rotors with lifetime warranty. I see where O’Reilly Auto sells the rears for around 47.99, which is not much more than getting regualar rotors with a time warranty. see if you can get the fronts that way, too. At least that minimizes the cost of the rotors if the pitting occurs again.

10K miles should be enough to keep the rotors in good shape, in my opinion. If there is any doubt about the two opinions offered by the mechanic and dealer, find an independent mech who can provide you with another opinion about why it happened.

I 2nd the opinion on checking the rotor swept area. However ensure you check both sides of the rotor which is best done if the wheel is removed. You may have a pad which is not contacting the rotor due to rust/dirt on the caliper sliding pin preventing full pad contact.

It is perfectly normal for rotors to rust on the outer edges and at their center.
Depending on atmospheric conditions, sometimes rust can speckle the rotors after a vehicle has only been sitting for a day or two. A few stops and it’s gone; no problem.

Regarding this grinding noise you’re getting; does this occur with every stop or only for a few stops after the vehicle has been sitting overnight, etc.?

[b]What you’re describing isn’t all that uncommon.

Pitted rotors are a result of inferior metal casting practices. When molten metal is poured into a casting, it must be done at a certain rate. If it’s poured too quickly, gas bubbles can form in the molten metal and leave voids in the casted material. These voids aren’t seen in the newly casted component.

When this happens with brake rotors, as the rotor surfaces wear, these voids begin to be exposed. And this is called rotor pitting.

Because these pits are below the friction surfaces of the rotors, rust forms in them because the brake pads can’t remove the rust. This rust builds up in the pits to where the rotor wears and the pads come in contact with this rust. This rust then begins to contaminate the brake pads. And an iron oxide contaminated brake pad or shoe will grind everytime the brakes are applied.

So, if the rotors are truely pitted, you need new rotors.



Your brake rotors were made with slave labor from “recycled” cast iron scrap. We did you expect? Benz quality? Sorry…

That wasn’t very nice.

Thank you for your suggestion. I wasn’t aware that there were brake rotors with lifetime warranties. I think I will follow your suggestion and purchase the lifetime rotors so I avoid any future problems.

Thanks a bunch!

Just be careful of any wear item that carries a lifetime warranty. All companies are in business to make money. If there’s a lifetime warranty on a part that is expected to wear out, there must be some way they can still make money on them. When a shop offers this type of warranty, they make it up on the labor to replace them. Sometimes, they actually wear out faster so they can replace them more often. Parts are free, labor is not.

While crudely put, Caddyman’s response was correct. “White box” rotors are made in China from low quality recycled metals and the labor is frequently prison (i.e. forced) labor. You should always stick with name brand rotors and resist the temptation to go cheap. At the end of the day you never go cheap on tires or brakes. A cheap spark plug won’t kill you but bad brakes and/or tires are a recipe for disaster.


These were the original brake rotors and pads installed by Hyundai. I did not sacrifice safety nor would I ever dream of doing so. Are you suggesting that Hyundai is using slave prison labor from China to produce their brake parts?

any other hyundai owners out there who can comment on the brake/ rotor longevity? im curious because the huge warantee hyundai gives MUST have SOME catch??!!


You can ask your mechanic to turn, or have turned by a parts store, your rotors. American cars have a stamped minimum thickness imprinted on them for how thick the rotors have to be, MINIMUM, for turning purposes. If you decide to have the rotors turned, (usually material is removed on a lathe-type machine in .001" increments), that’ll get the rotors down to new, clean metal. Then any cracks or really deep pits will show up. If they’re marginal, toss 'em and replace with new. It is always better to get rotors turned where both inside and outside surfaces are turned (cut) at the same time. Reduces/eliminates warpage during the turning process, but a good machine operator can cut one surface at a time if he/she cuts in shallow, slow increments. Sharp cutting tools are an absolute must. Dull cutters= crappy results. Of course, new pads get put on whenever you do any rotor work. Don’t ever let anyone cut more than the mandatory minimum. Rotors dissipate heat as they’re used. Too thin rotors crack, warp, and sometimes just flat-out disintegrate because they don’t have the proper thickness of metal to properly and safely dissipate the extreme heat that all brake systems generate. Guess when the most heat is generated? Emergency stops. Would you want your rotors to break during an emergency stop? The for-sure repair is to replace both rotors and pads with new. But if you implicitely trust your mechanic, ask his/her opinion. Cutting the old rotors down might turn out to be a waste of time and money, but it is another option that you might consider. Vehicle business happens where the rubber meets the road, including the brake system. Most times, it doesn’t matter how fast you can go. It matters more how fast you can stop. Of course, a good mechanic will check out the rest of your brake systems for leaks, cracked hoses, etc. Don’t cheat on the brake system. Your safety, health, well-being and life depend on those brakes. The same goes for other human beings and animals.

I just re-checked your original post. Only 26K miles? You probably don’t need to change out the brake fluid. However, another little trick that I do is to use a plastic turkey baster to remove as much fluid as I can from the master cylinder and replace with fresh, new fluid of the appropriate type. Again, ask your mechanic’s opinion. On my old junk, '92 Olds Cutlass ciera, '71 Chevy-10 L-6 engine, van with no power nothing, '85 Jeep Grand Wagoneer, (a.k.a.: Dragoneer), '92 GMC G-20 van, and my S.O.'s '89 Toyota Corolla AllTrac, (265K on it), I use all of these little tricks. With this old stuff, I completely flush the brake lines with denatured alcohol, blow air through the lines, completely replace the fluid, bleed and adjust. Of course, “while I’m at it”, I also carefully inspect the rubber seals on the ‘slave’ cylinders, just for the heck of it. Any cracks or leaks get fixed. The '71 van has 187K+, the '92 van has only 156K,(ONLY? ??), and the Dragoneer has about 147K. I won’t even discuss the '56 Allis-Chalmers WD-45 farm tractor. No gauges except for oil pressure and amp meter. I like old stuff. Old stuff works if properly maintained. Heck–I’M old stuff–and I still work pretty well.(Heh! Heh! Heh!).

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Sorry Everyone

You just drug up an 11 year old thread and you could have kept it brief for easier reading.

I know “the buck stops here”, but who seriously thinks a president is to blame for what the Chinese make brake rotors out of?


You made some blanket statements about low quality from China. How do you know that all rotors from China are junk? Also, I detect a sales pitch, since you tell us about your “high quality” alternatives. I replace my pads and rotors with mid-grade parts, and they perform well, no matter where they are made. I suggest you provide evidence for your claims.


It is a sales pitch . The last part of the screen name will take you to web site.
@cdaquila Me thinks Tom is using stealth spamming .