Already posted the story about why I had to change my rear rotor, but during the process I ran across something odd.


Here is a side by side shot of the new and old rotor. Looks like something is missing from the old one.





My question is: Has anyone else seen this before? Was this something that happened over time? Or does it look like what my dad and I think and someone cut part of it off? We did have one heck of a time getting the new one to fit properly, so that's why we are thinking they removed part to make it fit. If it is something that can happen just by driving, any ideas on what would cause it?

 

My sister was good at allowing her car to go WAY beyond time to service the brakes and eating the rotor. Rear brakes are often neglected as they really do not lend much to the total braking force of the vehicle.

What happens most often is the sliders fail and the outside pad grinds away until there is an audible noise. But the caliper pistons can freeze along with the sliders and grind away as well.

Most likely, what happened here is rust got to the rotor and caused the inner pad surface to break free from the rest of the rotor where it then snapped and fell off.

My old winter rat succumbed to rusty rotors on the front and ended up with a chunk flying up and gouging into the oil pan. It was a 1986 Ford Crown Victoria LTD Wagon that sat in my uncles back yard for 5+ years before I gave him a couple hundred dollars, tossed a battery into it, and drove it out. It leaked oil until I sold it to someone for $500 to use as a demo car. I used to know it needed oil when I would hear the lifters ticking! I got 2 winters out of it in highschool and made money even after the minimal repairs to the brakes.

 

ive seen that happen a few times. whats funny is most the time i drive the car before you dont really hear any grinding or funny noise. ive seen people wear them down so thin the hat actually busted off from the braking ring.

or seen solid rotors get worn down paper thin so it was like a giant razor blade. most the times customers dont bring their cars in until the piston in the caliper actually shot out

 

Thanks for the info. I figured it was possible, just have never seen it before, on any vehicle I've owned. Haven't done the driver side yet, due to time constraints, will probably go ahead and pick up another rotor and replace that side as well when I do the pads. It's probably pretty rusted too.

 

I had rotor that weren't as bad as that, but getting close on one of the trucks I bought. I'd look at changing the calipers too. One of the calipers on mine had cracked, I'm guessing from the impact loading of the rotor fins. Plus if you had a hard time getting the calipers over the new rotors then them might be too corroded to open all the way.

 

I just replaced the right rear rotor on my 99 Bravada. I could hear and feel the pad(s) scraping on the rotor for a cupla weeks before it finally dropped the pedal almost to the floor. Turned out to be the inside pad, completely worn down to the metal. Outside still had a lot of pad. The inner pad grabbed the rotor then slid out from the caliper, causing the caliper to come most the way out and press on the rotor. Driver's side still has lots of pad.

But I suspect the fact I've been driving mine for almost 2 years with a muffler that rusted off the tailpipe is what did mine in, because everything behind that muffler looks to be in much worse shape corrosion-wise than on the left side. The right rear brake backing plate is completely gone, too, whereas the left is just fine. In addition, the parking brake... WHAT parking brake??? It was obvious the parking brake shoe lost its pad long ago and has never contacted the drum surface for months if not years.

So I replaced the right side rotor, pads, and parking brake. Haven't gotten around to the left side yet since it's in such good shape. ASAP, I'll also replace that muffler and long-gone, missing tailpipe.