FAQ: Vibration under braking: warped rotors? NO!

[itguy61]

Well, because of everyone here saying to ask and what to say, I did that and they are covering it. The dealer contacted Kia on my behalf. They are resurfacing the rotors as a courtesy warranty. Thanks everyone for the tips.

Did you replace the pads with something else? If not, you have a temporary fix.

 

[Ulikefishsticks]

I had my rotors resurfaced about 3 months ago. The shuddering is already coming back. I have going to push them to resurface them and swap out the front pads. As I understand, the majority of the shuddering is coming from the front brakes. As soon as Stop Tech gets the rear pads back in stock I will swap out those also. Hoping that this will finally end the problem.

 

[MerlintheMad]

I had my rotors resurfaced about 3 months ago. The shuddering is already coming back. I have going to push them to resurface them and swap out the front pads. As I understand, the majority of the shuddering is coming from the front brakes. As soon as Stop Tech gets the rear pads back in stock I will swap out those also. Hoping that this will finally end the problem.

Either this thread or one of the several other "brake" threads, says up there somewhere that if you feel the "judder" in your seat the deposits are on the rear rotors; if you feel the "judder" in the steering wheel then the deposits are on the front rotors.

 

[Blingen]

I have not replaced the pads yet That is next I remember seeing some recommendations on this site. I just need to find ot again

 

[DirtyDave]

Had the pulsating brake issue crop up recently and had Khartunerz replace my front pads with Girodisc pads. They tried to resurface the rotors unsuccessfully so I also had them install Cquence front rotors. My right leg is so much happier now when I'm braking.

 

[SeanFL]

Only 2000 miles on my Stinger and braking is still very good. After reading all 22 pages, I have a question please. Seems like the consensus is this braking problem is caused by the brake pads and rotors heating up. If I am a relatively conservative driver, very little or no "spirited driving", or driving that causes the brakes to heat up abnormally, will I have this braking problem with my rotors?

I have kids in my car much of the time and don't brake hard. I anticipate what's happening with the lights, try to downshift with the paddles when possible, and have very infrequent hard stops. My prior Lexus IS350 made it to 80,000 miles before needing new pads. All that said, the shudder has happened to me twice in 30,000 miles on my GT2. Very disappointing...now searching for the right pad to swap out and see if I'll get more than 12,000 miles between braking problems.

 

[Ecco]

Had the pulsating brake issue crop up recently and had Khartunerz replace my front pads with Girodisc pads. They tried to resurface the rotors unsuccessfully so I also had them install Cquence front rotors. My right leg is so much happier now when I'm braking.

How are rotors unsuccessfully resurfaced?

 

[ShannonC]

How are rotors unsuccessfully resurfaced?

Maybe too thin otherwise should not have been an issue?

 

[itguy61]

How are rotors unsuccessfully resurfaced?

They measure the thickness and fail if not a minimum thickness due to too much wear.

 

[eflyguy]

How are rotors unsuccessfully resurfaced?

When the customer is uneducated and the shop happens to sell replacements.

 

[G-796195]

Not enough material on rotor to work with.

 

[StungBlueGT2]

now searching for the right pad to swap out and see if I'll get more than 12,000 miles between braking problems.

I had my rotors resurfaced then completely replaced then resurfaced again but the shudder kept coming back until I switched the pads. Houston at Cquence recommended Akebono Performance Ultra Premium ceramic pads and haven’t had the issues again.
Akebono PERFORMANCE Ultra-Premium Ceramic Pads Completely eliminated the vibration issue, and overall braking is much better than the OEM crap pads we got stuck with.

 

[DirtyDave]

How are rotors unsuccessfully resurfaced?

I was told that the brakes continued to chatter some after they resurfaced the rotors. Said they just couldn't get the surface even. Said it might go away after some braking with the new pads. I decided to just upgrade the rotors and be done with all the suspect parts.

 

[Helo58]

How are rotors unsuccessfully resurfaced?

In rare instances, the damage to the rotors cannot be machined off due to the depth that the damaged has reached. The localized hot-spots on the rotors due to the pad deposits will cause the iron to turn to cementite over time. This is actually a change in the metallurgy that penetrates into the rotor rather than being confined to the surface. It is highly doubtful that this would be observed at the time the rotors were machined, but would show up later as the pad deposits and vibration returned more frequently than they appeared in the initial case. If cementite is present, turning the rotors or aggressively bedding the brakes will not fix the problem. The rotors must be replaced at this point.

It is also conceivable that the shop presented the cost of machining the rotors to the customer and then told them that it would make more sense to spend that money on new rotors rather than repairing old ones. Considering that I have seen Stinger front rotors sell for as low as $77.00, I would go for the new rotors myself rather than machining old ones. Performance rotors should never be machined because it diminishes their performance in a number of ways.

 

[DirtyDave]

When the customer is uneducated and the shop happens to sell replacements.

Thanks for your highly educated guess.

 

[StingerJeffON]

thefultonhow: If the rotors aren't warped, can I replace the pads without replacing the rotors? What I read seems to make me think that I can do the Re-Bed and then change the pads before they start to cause the problem again. What if I don't re-bed before I change the pads? What pads are a good middle ground for a daily driver. I don't want noise or dust but I don't want vibrations even more. Mild dust with quiet would be my preference if such a thing exists.

 

[MerlintheMad]

thefultonhow: If the rotors aren't warped, can I replace the pads without replacing the rotors? What I read seems to make me think that I can do the Re-Bed and then change the pads before they start to cause the problem again. What if I don't re-bed before I change the pads? What pads are a good middle ground for a daily driver. I don't want noise or dust but I don't want vibrations even more. Mild dust with quiet would be my preference if such a thing exists.

Lurker! Welcome into the open.

You've been on here long enough to know the answers, on just this thread alone. But here's the short version: "warped rotors" is a phrase to describe lumpy/juddery/shuddery feeling brakes. The rotors are still perfectly straight. But they may have developed "hot spots" where cementite has formed; this goes below the surface, i.e. makes any resurfacing pointless and feckless: new rotors time. If the problem is merely crappy pad deposit buildup, that can be surfaced off: but, it can also be rebedded off. Do the rebedding procedure to determine if you have deposits only, or cementite: if the latter, the rebedded pads will fail to smooth out the feel of the brakes. If rebedding makes your brakes smoother, then get new pads on right away. I, too, would prefer a little dust to lumpy feeling brakes any day! (my OE brakes have been fine for over 32K miles and tested/checked out as "good" this week)

 

[StingerJeffON]

Lurker! Welcome into the open.

You've been on here long enough to know the answers, on just this thread alone. But here's the short version: "warped rotors" is a phrase to describe lumpy/juddery/shuddery feeling brakes. The rotors are still perfectly straight. But they may have developed "hot spots" where cementite has formed; this goes below the surface, i.e. makes any resurfacing pointless and feckless: new rotors time. If the problem is merely crappy pad deposit buildup, that can be surfaced off: but, it can also be rebedded off. Do the rebedding procedure to determine if you have deposits only, or cementite: if the latter, the rebedded pads will fail to smooth out the feel if the brakes. If rebedding makes your brakes smoother, then get new pads on right away. I, too, would prefer a little dust to lumpy feeling brakes any day! (my OE brakes have been fine for over 32K miles and tested/checked out as "good" this week)

Yeah, I haven't been active on the site. Luckily, I haven't had any real issues with my Stinger so I haven't had to research any problems and I haven't felt the need to modify my GT since it already has more power and performance than I can use living in the city. It is already the most fun car I have owned or driven. I don't feel any real need to change a thing (except maybe the brake pads....lol).

 

[MerlintheMad]

Yeah, I haven't been active on the site. Luckily, I haven't had any real issues with my Stinger so I haven't had to research any problems and I haven't felt the need to modify my GT since it already has more power and performance than I can use living in the city. It is already the most fun car I have owned or driven. I don't feel any real need to change a thing (except maybe the brake pads....lol).

Other than the "haven't been active on the site", I could have written that word for word.

 

[Helo58]

Other than the "haven't been active on the site", I could have written that word for word.

@MerlintheMad , active?? Hardly... It has been at least 90 seconds since your last post.