Is it possible for Rotors to "unwarp"?
 

Hey all. I think lately my rotors seemed to have corrected themselves. Usually when I brake moderately from 60-70 I get the shuddering from the rotors but last week I stopped hard a few times and now when I stop from 60-70 theres no more shuddering. Could braking hard those few times have somehow rewarped my rotors straight? :)

Re: Is it possible for Rotors to "unwarp"?
 

I think it's unlikely, but I will tell you that my rotors are a little inconsistent. They'll be fine until I stop hard. And then once they're heated up from that, there's a pretty harsh pulse in the brakes until they cool down again.

There was a lot of discussion on this subject a while ago. One expert opininon suggested that some of the pulsing that is experienced is actually not warpage, but deposits of brake lining on the rotor surface. These deposits can be removed by a few hard stops. Perhaps this is what you have experienced.

Matt

I unwarped my wifes rotors by torqueing all the lug nuts equally. I'm still in disbelief but so far it has not had any shudder since I did this and it used to all the time.

Out of interest I have been following the many posts regarding " warped " rotors ( what we call the disc as being a component of a disc brake assembly ) and there would seem to be confusion in the use of the term. Surely a warped rotor is one running laterally out of true and is in effect bent and not one which has surface defects.

Do all reporting rotor problems use the term correctly ? Or inadvertently are two quite separate problems being reported as being the same, in which case the issue has become completely confused.

I believe there is confusion of terms here. We are using "warped rotors" as a blanket term to describe the pulsating brake pedal feeling and/or shuddering of the steering wheel under braking.

Therefore I AM confused. Which is the endemic problem ? Bent rotors or rotors worn so that the surface is out of true ?

It is reported that lug nut tightening can produce the problem in which case latteral run out must be the problem. It would appear that there IS real confusion here.

Disk warping.
 

Morning Trev.
The disk does warp when hot, because it is a sand casting that varies, in the thickness of the metal in the disk area.

In production the casting is grabbed by the jig to machine the surface, if the jig holds it a bit off line, the metal in one area of the disk is thicker, than the area diametrical opposite. The two faces are still parallel but of varying thickness so the expansion rate is different around the surface,so warping happens. The warping disappears when the disk cools.

The other way, is if the wheel nuts are torque unevenly. This type of warping is really run out, caused by distortion. Torquing the nuts to an even 80 ft /lbs will cure this one.

Harvey.;)

Yes, yes Harvey I know all that which is why I raised the query. Some appear to be quoting uneven wear or build up as being the same problem. I define warping exactly as is stated in all dictionaries but confusion could be lumping the two issues together.

Re: Is it possible for Rotors to "unwarp"?
 

Warped or bent or filled with crap, I have gotten rid of the pulsing on a few cars now by jamin on the brakes hard several times in succession.

Nice to hear it worked for someone else. :)

Always worth a try,as long as pads are still good, before turning rotors or rebuilding sticking calipher pistons. :)

Re: Is it possible for Rotors to "unwarp"?
 

Well, it worked!! I stopped hard a few times from 70 mph and my brakes are definatly improved. I had quite a shudder before and now it is just a very mild shudder.

Tapper
:)

Using a torque wrench and some hard stops seems to be working for me also.