Rotors Cracked

98 prelude 115K miles. I just replaced the rear pads first time due to
rusty hand break linkage. The non vented rotor had discolored lines
that ran jagidy perpendicular to the bright wear ring. These I assume
resembled/was due to cracking. I looked on the front vented rotors and
the same thing. I don't know the rotor thickness specifications but
the rotors did not appear to have much wear. i.e. there was just a
slight lip 1/16" or less. I am interested in hearing if any body has
heard of rotors where chunks cracked off.
Are the cracks enough to make replacement of the rotors mandatory?
thanks tom

 

Let's put it this way:

If your rotor loses a chunk, all hell will break loose when you apply
your brakes. If it is in a hard emergency stop, you will have much
less control over the braking and possibly steering of the car. It's a
bad thing, and it can and does happen.

It sounds like they've been badly abused.

 

Take them to a resurfacing shop. They will tell you if they are cracks or
just surface blemishes. All answers you get here without being able to see
them will be just guesses...

 

wrote in

You appear to be in Wisconsin. That means you are susceptible to severe
rust, like that shown on this page:
http://www.tegger.com/hondafaq/rustybrakes/brakes2.html

From your description, it sounds like you've got rust buildup around the
perimeter of the disc, and that rust is flaking off. There's a quick way of
shaving that off.

Cracks that impair the rotor's structural integrity would be visible within
the bright area. If the swept (bright) area of the disc does not show
cracks, then you're fine.

 

I have only had cracks on my cross drilled rotors which I will never buy
again.

 

yes, /much/ more likely this is it. actual disk metal cracking in the
braking or hub areas is very rare. and catastrophic.