Front wheel shimmy when braking

[don280z]

My front wheels have developed a shimmy when braking from high speeds (50+mph).

It feels like the rotors are warped.

At slow speeds (0-30mph) it is OK.

Also, it does not seem to shake until the car has been driven for a few minutes - possibly because the brakes/rotors are still cold?

Can the rotors warp when they get hot, and straighten back out when they cool down???

Thanks...

[Scotty]

Here is an interesting article on "warped rotors"

http://www.stoptech.com/whitepapers/warped_rotors_myth.htm

The term "warped rotors" is a misnomer, most of the time the shudder is caused by the transfer of brake material to the rotor and the rotor becomes GRABBY....

If your pads are in good shape you may be able to have the rotors cleaned up and resurfaced to stop the shudder you are getting and use the existing pads. Do a search on 'bedding the brakes" here so that you break them in correctly (no pun intended).

The fronts you can feel in your steering wheel, to see if your rears are shuddering, drive at highway speed and press your emergency brake and see if you get shudder (with no one behind you). Mike

[Ranger]

No, if they are warped, they are warped but that is not your problem. You have uneven brake pad deposits on the rotors. Take them in and have them cleaned up. Just a light skim cut is all that is needed even if they look good. Trust me, I just went throught this with my daughters Taurus. She was selling it and it had a terrible brake shudder. I pulled the brakes and the rotors were clean and smooth. Even used some sand paper on them. No go. Pulled them and had them skimmed. Stopped smooth as can be. This link will explain it better than I.

http://www.stoptech.com/whitepapers/warped...yth._german.htm

Edit: oops, Mike types faster than I.