Hello everyone. I had extreme vibration when I hit the brakes recently and I decided to check out my rotors. The rears looked very worn and felt uneven when I dragged my finger across them, but the fronts are very smooth and look like they are fine (I'm at 55k with the original rotors). So I decided I would change the rear rotors and replace all four brake pads on my car, and also replace the steering stabilizer.

I ordered 2 Balo rotors for the rear and Akebono pads for all 4 wheels. I also ordered the stabilizer from joetlc. After replacing the rear pads and rotors, the steering stabilizer, and the front pads I would say the vibration decreased by about 80%, but there is still a vibration when I brake although it is much less. So I decided I would try to get the front rotors turned since they are more expensive to replace. When I took them to get turned, the guy told me that he couldn't turn them because they are too thin but he said at the same time that they appear in very good condition and do not need to be replaced. What he said really doesn't make sense but since whatever they have on record for minimum thickness for our rotors, it wouldn't let him turn them.

So now I am confused, they really do appear fine and I don't think they should be worn out by 55k miles but I am still getting vibration when I hit the brakes. Is there anything else that could be causing this besides a warped rotor? All my calipers and pistons appeared to be fine during the change.

Also, I am now hearing my brakes squeak as I am driving but it stops when I hit the brakes. This noise was not there before. I applied the brake grease on the back of the front pads, but the rears did not come with any grease. What could be the cause of this noise?

Sorry for the long post, just thought I'd share my situation in detail. Thanks in advance for any advice/input.

 

Personally, with brake trouble you are having, I would have replaced all 4 rotors if replacing the pads all the way around. Why cheap-out on the part of your car that does most braking? Your front brakes do at least 80% of your stopping the car. Generally, the fronts will warp before the rear. There are exceptions.

Good luck, James

PS Vibration from the brakes is not always from warpage. You could have hard spots in the metal (rotors) causing the same symptoms. Sometimes it can be seen, and sometimes not.

 

I looked at my brakes, which use Akebonos, because they squealed. I applied the brake grease when I put them back together and the squeal was gone. There was no grease before so that solved that problem.

I am going to replace the rear rotors as they are quite scored and get the old rotors ground. I will also fit new Ideal pads all around as I think the Akebonos are too harsh sounding.

I looked at SparkieSRT6's rear rotors and they were scored as well. His front and my front rotors are quite smooth, which is strange.

 

First, check that the lugs are torqued correctly. Next check that the front rims aren't bent. Do you have spacers? I find it unlikely that the front rotors are warped under normal usage and my best guess would be a bent rim.

Les

 

I do not have spacers, everything is stock except the sound system. I have looked at the front rims and they do not appear to be bent. If they were, wouldn't it cause vibration without braking?

I will apply brake grease to all the pads to see if it helps with the squealing.

Thanks for the input guys.

 

I bent two rims on a pot hole. Immediate vibration above 30 mph, smoothed out above 65 mph. No difference when braking. Just my experience.

James

 

If the rotor is warped then you can feel some vibration through the brake pedal. Is that the symptom?

NA rotor thickness, front =28mm (new), minimum = 26mm, rear =9mm (new), minimum =7.4mm
SRT rotor thickness, front = 32mm (new), minimum = 30mm, rear = 22mm (new), minimum = 20mm

Minimum size above is the service limit, that is the minimum size after machining. Wear after this not exceed .6mm total and only .3mm total on the NA rear rotor.

There are some size errors in the Repair manual.

 

If they are thin then they will warp much easier. If the vibration is only when you brake it is most likely a warped rotor.

 

Sorry for the delay guys, been really busy.

And yes there was vibration through the brake pedal during braking and also through the steering wheel.

Anyways, had a friend of a friend who was a long time mechanic and claims to have replaced hundreds of brakes over the years take a test drive. Before we even got down the street he said it was a warped rotor(s).

So that same day I ordered some ATE Premium Ones for the front ($45 each + shipping), showed up at the door the next day.

I installed the drivers side first with no problems. Then, when I got to the passenger side I encountered a strange problem. The hole for the single bolt that secures the rotor in place was not large enough! I had to take the rotor off and tap the bolt through the hole from both sides to make it large enough to fit, even then it was still such a tight fit that it took a great deal of strength to tighten it.

After finally getting it on, I gave the rotor a spin and to my dismay it was ridiculously uneven! I put the original rotor on to check that something else was not the problem, and the original spun much straighter than the brand new rotor! Needless to say there was something wrong with this particular rotor, I am shocked that it passed the Quality Control of a reputable company like ATE.

So the next day I called Tire Rack to see if I can get an exchange and they had a hard time believing that the brand new rotor was warped. They asked me to take a picture and send it to them I asked them how I was supposed to take a picture of a warped rotor and then they suggested that I take it somewhere to have them measure the run-out Really I cannot believe they are making it so difficult for only a $45 part.

Well I can't wait to get the new rotor in and finally be done with this project. Will be nice to have a smooth comfortable ride once again.

Thanks to all the members who took the time to share their knowledge on this subject, it has been most helpful. I will hopefully post the good news when I am done or the bad news if I encounter any more problems!

 

No offense, but if it were me and I have been selling and installing performance brakes for a little more than 10 years...If one rotor comes warped to you....Why on earth would you want to go with that same company again? Spend the money on a product that secures you up front. There is a lot of garbage being sold online and I hate seeing people get ripped off on a daily basis.....I need to do another write up on bad rep brakes and good ones to buy. If you ever have any questions or concerns on brakes please send me a pm.

 

None taken. However, its not like I bought a cheap pair of rotors and they came warped. I believe ATE is a reputable company, considering that the brake calipers on our cars are made by ATE. Also I believe the ATE Premium One rotors have a good reputation. The reason I got them for that price is because I get an employee discount. I believe without the discount, thats about how much the rear ones go for online. And the reason I didn't order them for the rears is because they were out of stock.

Anyways, the good news is that they sent me a replacement and the vibration is gone.

 

My guess is the rotor is not warped, if the screw is too tight I would guess that the rotor is not tight up against the hub. If the screw is hard to turn then it may have cut a slight thread in the rotor and you can not tighten two items together when each carries a thread until one of the threads is stripped by the tightening forces. It actually may feel tight, as the screw side will be tight and the other side will be clamped down by the screw side force. A rap with a hammer on the top hat may loosen it though. Also the screw may be stripped by now and it may indeed be a warped rotor.

If you have a run out that is easily visible then that is extreme run out, normally you would need a dial indicator to see a run out that would cause some vibration. I think .004" is the max T.I.R. in the shop manual, I could be wrong on that though.

Strange he mentions the rear rotors as being badly scored, as SparkieSRT6 and I have badly scored rears and smooth fronts.

Well the answer came as I typed so the outcome is positive.