warped rotor?
 

hi, i have a 95 R2.
i get that jerky/suttering when i brake and slows down. the jerk as if the brakes were applied for a second, and left off, and reapplied, let off...

do you think it's a warped rotor or is the aixle shot? need advice please. thanks.

Probably some warped rotors. "Thick-n-thin" is a better description technically, but everyone calls them warped for brevity (including me :)).

This is a known issue that many owners have had before. Get some new rotors (OEM or Brembo blanks and my recommendations) and it will probably go away. You could also try having your current rotors turned at an auto parts store as a diagnostic aid, but chances are that they would warp again quickly. The turned rotors should be fine to drive on until they warp again, though. They will probably be too thin to turn again, so you'll likely need new rotors after that. If that fixes the problem, you'll know its the rotors.

To help reduce the chances or warping the rotors again (though even with careful use they can warp), here are some tips:
- don't do a hard stop on cold rotors
- don't sit still after a hard stop (roll a little if you get caught at a light after a hard stop to help the rotor cool uniformly rather than making a hot spot under the pads)
- don't use the parking brake right after heavy brake usage -- use wheel chocks if you are at the track or just drive around for some "cool down" time if you were tearing it up on the street

I often think of the front brakes when I feel the pulsing, but I found that my rear rotors were once the cause of the pedal pulsation.

-Max

It's also common to have uneven buildup of residue on the rotor surface. This gives the same pulsing symptom as a truly warped rotor. Some people even claim that there are few, if any, truly warped rotors, and that such residues are the true culprit.

Turning, will of course remove surface residues. However, chucking an abrasive pad into your drill is worth a shot if you're doing your own work.

See this link for more info:

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