My car is a 2009 base with z51 package with 38k miles. My question is all 4 disks have a lip around the outside edge that looks like they are wore down that much. Is that lip normal on the brake disks, or do they need replaced. If I saw them on any of my other cars with a lot more miles I would think they are worn down. But this car doesn't seem to be beat on, and is a pretty low mile car. All 4 disks have this lip also. Brakes operate fine, stop perfect, now wobble, or pull to one side.

Thanks

 

Brake discs are normal wear parts and yes it’s normal for to have the lip due to normal wear. It all depends how much wear which is usually measured by calipers as when when they need replacing. How much pad material is left? when was the last replacement? How hard is the car driven? It would be a good idea to replace pads, rotors and fluid in a 11 year old car if they’re original parts and even if it was done before those questions really come into play.

 

Z51 HD brake pads will wear out in about 30K miles and since they are very aggressive pads to give the extra initial bite and feed back, then will wear the rotors on the faster side as well.

The z51 rotors with the HD pads are good for about 60K miles, so if you are on your first set up pads (up to the 30K), then the discs/rotor can be pulled and turned to clean them up. Hence the rotors wear faster on the outer edges, then then inner hubs, so not only will it remove those end non wear lips, but will square both sides of the rotors to each other.
Note, rotors can only be turned once, and this is done at the 30K mark where the pads are replaced. At the 60K mark, not enough meat left on the rotors to be turned a second time, so they are replace with the second replacement set of pads at the 60K mark.

As for the lips on the outer edge of the rotors, not really a problem before you do wear out the pads, but if the car does have say 40K miles on it and the pads are still thick, someone may have replaced the pads without having the rotors turned. So if such is the case, then not a bad time to pull the pads and rotors to check on them, to not only have the rotors turned, but to make sure they did install HD pads back on the car. Hence could have installed some cheap base type ceramic pads, and gave up the much improved initial bite, way better pedal feed back, and even the higher working temp ranges of the HD pads.
Note here, brake fluid get power flushed every 2 years like clock work, and even more if you are road racing the car to get the brake fluid up close to it boiling point. Also, if someone can not feel the difference between say Duralast ceramic pads and the way more aggressive OEM HD pads, will bank that either the brake fluid has not been changed, or never get into the brakes hard enough to feel the difference.

And yes, you can turn drilled rotors, but they need to have the dampening belt installed on the OD of them/shallower cuts to make sure that the surface is not chatter city, and will cost about $5 more per rotor to turn them over a none drilled rotor.

So on that note, what mileage on the car, what pads, and a photo of the rotor lips, to see if its the remaining pad amount before turning that you are seeing, or if the pad has been changed but rotors not turned at the same time.

 

Thanks, The pads look good, but I plan on replacing them and the fluid when I get home. I don't know anything about the past of the car, but the condition is almost perfect. Seems like it was very well taken care of. I bought it a little over a year ago and while I have driven it fast, I still haven't got real hard on the brakes. The lip just seems abnormal to me. So my question really is, do the new disks have any kind of lip, or are they perfectly smooth all the way to the end?

 

Thanks for the info. I can't get pics right now. Sitting in quarantine, and leave for South America in the morning. Trying to figure out what I need to order so that when I get home I have everything. Car has 38k miles. Don't know the pads. just know that they have a lot of material left. I am thinking about just ordering new rotors and pads. I live in a very small town, so finding someone that can turn then might be a issue.

 

Any recommendation on a good set of disks and pads?

 

The face of the new rotor will be flush all the way across the contact area,


And here is front and back Z51 rotors after turning at the 30K mark when new HD pads were installed, with a few hundred miles on them.
Attachment 48339776
Attachment 48339777

 

Thanks, that is what I am used to seeing. Just never had a corvette before. Will start shopping for a set of new disks and pads. Any recommendations are appreciated.

 

Again, pull the rotors, have them mic'd, and will bank that they can be turned for cheap, instead of being replaced that will hundreds of dollars more.

Around my area, Its $15 to turn a drilled rotors, and will clean up/remove the ledge lip on the back rotors drum for the E brakes, so you can adjust the rear brake e shoes during the brake job.
Note, C6 E brakes are not self adjusting, nor have a back slot to get an adjustment wrench it that way, so to adjust the E brake shoes, you need to pull the rotor, adjust the E show aduster, put the rotor back on to check/pull the rotor back off to fine tune the adjustments in the end.

As for pads, if you are running autocross, then OEM HD pads again, but if just street use where your not glowing the rotors like in autocross, then Bobcat 1521's.
The 1521's have less dusting, slightly lower working temps, but you will not give up initial bite and pedal feed back of like the HD pads.
Note, if you are going to stay with HD pads, make sure they are the HD pads, and not the base less aggressive pads. Both sets of pads are the same size, and its the pad material that is different.

As for power bleeding the brake fluid, go with Prestone Dot 4. It has the highest boiling point for a quart of fluid that will be under $20.
There are better fluid for racing that have higher boiling points, but your looking at $80 for a quart of it instead.
Also, will need at tech II to cycle the ABS pump to get the old fluid out of it to begin with.

 

Wow, thanks for the info. Going to have my wife call around for me to see if anyone around me can turn them. My best chance will be the NAPA store I think.

 

If you buy new rotors I got Delco rotors from rock auto for around $250

 

Thanks, going to see if these can be turned first.