2012 brake rotors 'warped' at 16K miles

microvan

Member
:
2012 Mazda5 GT (sold)
Searching the archives, there doesn't appear to be an overwhelming occurrence of 'warped' rotors on the latest generation 5. However, at 16K miles I've got the brake rotor shimmy.

What has been the track record on rotors of other 2012+ owners? Anyone have them machined this early? I'm thinking I might just buy a quality aftermarket kit and have my shop install it rather than waste money machining garbage rotors.
 
I have about 18K, just have a very mild pulsation, so mild, did not notice under mild braking.
You can overheat and damage rotors in a single hill descent, so hard to say what happened.
 
I have about 18K, just have a very mild pulsation, so mild, did not notice under mild braking.
You can overheat and damage rotors in a single hill descent, so hard to say what happened.

No long descents around here, just short, sometimes steep hills. I'm also fairly easy on the brakes, using engine braking far in advance.

I also get a steering wheel shimmy at highway speeds, and I'm convinced the cause is the crappy Toyos. I've had them balanced more than once, but it's much more pronounced after the car sits a day or two without driving.
 
I have about 18K, just have a very mild pulsation, so mild, did not notice under mild braking.
You can overheat and damage rotors in a single hill descent, so hard to say what happened.

I have the same mild pulsation....but it's not at all noticeable unless the brakes have heated up. I have 38k miles on the odometer.
 
Have you tired going back to the dealership to see if they will do anything for you under courtesy?

Here in Canada, there's a general rule 20,000 KM or 1 year, the dealership will take care of it under warranty. Not all dealerships do this as brakes are considered wear and tear items not generally covered.

I've seen posts where there has been improvement in vibrations after taking some sandpaper to the rotors cleaning up the rust and some high spots.
 
I'd go and machine them at the local cheap shop.
Should be $10 to $15 each at most.
 
There are several causes of the rotor warp or pulsating feeling, and it would be helpful if we identified the source.

Wheel nuts installed with an air gun instead of a torque wrench at a tire rotation. (puts the rotor slightly warped, but usually only felt when braking at highway speeds or off-ramps. Have you had your tires rotated yet?)

Dirt or rust between the hub and the rotor flanges. (puts the rotor out of true, but you will usually feel it pulse when braking at all speeds)

Pad deposits on the rotor face will also cause a warped sensation when applying the breaks. (these can be removed with some sandpaper, no need for a lathe)
 
Last edited:
I'm the only one who's ever rotated the tires, and I've always used a torque wrench. I put "warped" in quotes because my understanding is that most vibrations are caused by deposits on the rotors. I did examine them myself and there is no obvious areas of deposits, but honestly I don't know exactly what to look for. They feel smooth to the touch. I'll probably just bring it to my local shop and ask them to turn the rotors. If it persists, I'll probably go with some decent aftermarket rotors and pads. I've never been thrilled with the braking performance of the OEM equipment anyway.
 
Put me down as one of the conspiracy theorist that think/believe the quality of the OEM rotors are just garbage. I believe they are cheap due to a high ratio of reclaimed metal vs pure metal ores in their composition, like cheap aftermarket rotors. I think they can (not ncesary is) contribute to hwy shimmies and pulsation when braking. This is just my speculation, not a factual statement. Goes along the line that Mazda seem to generally have a crappy supplier network and struggling to make money before the Sky* crazy that got them attention. Coincidently, Mazda seem to have fixed their quality issue in their new line of cars, post Ford –just saying *puts on tin foil hat*.

Quality replacements are not much more than having to take off the OE ones and getting them resurfaced. The effort to take them off + having to make errand runs back and forth to the shop is not worth it –IMO.
 
Last edited:
Well, brought it to the shop this morning, and it turns out the culprit is the crappy Toyos! I should have known, as the vibration was only in the steering and not the brake pedal. The tech was also surprised at how loud the tires are - I guess I just got progressively used to it. I paid for wheel balancing, hoping that might help, but it doesn't seem to have improved much. Time for new tires I guess.
 
I'm the only one who's ever rotated the tires, and I've always used a torque wrench. I put "warped" in quotes because my understanding is that most vibrations are caused by deposits on the rotors. I did examine them myself and there is no obvious areas of deposits, but honestly I don't know exactly what to look for. They feel smooth to the touch. I'll probably just bring it to my local shop and ask them to turn the rotors. If it persists, I'll probably go with some decent aftermarket rotors and pads. I've never been thrilled with the braking performance of the OEM equipment anyway.

"Smooth to the touch" THAT'S the problem! After they are turned, they will feel a bit gritty, like cut steel. Mine felt soft and smooth like a doll's plastic arms, and I think that's what it was covered in - plastic garbage from the garbage OEM FOMOCO pads! Turned them once after doing the Centric ceramic pads, and stopping is fast and predictable.
 
I been having same problem on 2010 model with 47k miles. Its been progressively getting worse in the last 12k miles. So today I sand both front rotors using 320 grit sand paper and re lube the caliper pin.

I do not like the design of the caliper pin. They are not well protected and would easily get siezed. This thing would need maintenance yearly for sure. You would need 7mm allen wrench too. No normal allen wrench set came with 7mm wrench. Got to take break from the job and went to Lowes to get 7mm allen socket.

The vibration are completely gone when I took a test drive and re bed the pads. I highly recommend sanding the rotor to clean any uneven pad deposit and relubing the caliper pin frequently.
 
Last edited:
What did you use to lube the caliper pins? Did you use the Permatex clear grease?
 
Late report. Thanks for the suggestions. Re-shoed the wheels with Hankook Ventus s1 noble2 tires. Big improvement and hardly any steering vibration, except at highway speeds sometimes - only when the wheel is on dead center, and even then it is very subtle. Did have the car back to the shop that installed the tires to have them rebalanced, which reduced the vibration further, but didn't fix it entirely. Tech there chalked it up to a belt on the tire causing a bump, which I don't buy. I've called a local performance shop to see if he can look into the problem.

Haven't done anything with the rotors yet, but will probably address that problem in the spring when it's a bit warmer. Replacing the tires did reduce the amplitude of the brake judder, but it's still there.

FWIW, the Hankook's are pretty nice. Quieter than the OEM Toyos, but also a bit more flex in the sidewalls. They do thump a bit over bumps. Wet traction is great and hydroplaning is minimal. Hit some pretty big puddles during a recent snow thaw and was impressed at the sure-footedness of the tire. Traction in light snow (1"-2") is also better than the Toyos, and better than the set of Continental DWS I had on a Subaru.
 
Last edited:
Better than the DWS? That's high praise! Most people seem to take the DWS as some holy grail all season tire. Or maybe that's just the tire store since the price is so high. :)
 
Better than the DWS? That's high praise! Most people seem to take the DWS as some holy grail all season tire. Or maybe that's just the tire store since the price is so high. :)

I did like them, and actually think they flex a bit less than these Hankook's, but I wasn't at all impressed by their performance in the snow. And I'm not talking about deep snow, which any all season tire would struggle with; I'm talking about 1"-2" of fresh powder or slush.

The Hankook's are listed above $100/ea, but I got the rebate which brought them down to about $80/ea.
 
wow! i second that. I had DWSs on two cars and they are absolutely the holy grail lol. I didn't put them on the my current Mazdas only due to price.
 
Update: had the wheels/tires road force balanced and got a 4 wheel alignment. They confirmed all four wheels were slightly out of balance, corrected the problem, and their opinion is that the tires are not a problem. They found the driver's front wheel toe-in was out of spec, as was the steering wheel centering. Fixed both issues.

The vibration is much improved, almost gone, but there's still a very, very slight shimmy at highway speeds. Maybe I'm just being too sensitive and it's simply feedback that's normal for the 5. But if any of you are cruising on a smooth highway, steering wheel centered, if you touch a finger on the bottom of the wheel, do you feel a very slight shimmy? If I hold the steering wheel firmly with both hands, I don't feel it. But I do feel it ever so slightly if I'm on a curve at highway speeds.

Also, my brake judder has nearly disappeared! I do still feel a subtle vibration when braking, but to me it feels similar to what I feel when cruising at highway speeds. Maybe it is a rotor issue, and the balancing and alignment helped minimize the judder.

I realize the pads run close to the rotors. Is it possible that deposits on the rotor, or a slightly warped rotor, contact the pads at high speed and cause the vibration? I've never experienced this with any other car I've ever owned, so seems far fetched. The rotor would have to be severely warped to catch the pads when the caliper piston is open, wouldn't it?
 
Back