TRUOMEGA

From the base 08 c6 coupe.... I just finished upgrading to the new z51 brake setup. I changed the bracket, the rotors and installed ceramic centric brake pads.
So im braking them in using the procedure that most use. I went to go get fuel and looked at the rotors. The front ones seem to be uniform but the rears, only half the rotor seem to be touching the pad. I was under the impression that the rear calipers were pretty much the same. I know the front ones are from the z51. Are the rear calipers that much larger on the z51 that the whole rotor surface will be covered? Thanks.

glenB

actually, the Z51 calipers have a smaller piston

front calipers are the same

Give it some time to wear the rear pads in, you also may be getting some flex in the caliper to account for the reduce surface area. I wouldn't be too concerned with it, either way.

TRUOMEGA

Actually... I think i see whats going on. I took a second look and noticed that the bottom half of the rear pads, for some reason haven't gripped the bottom half of the rotor. Only half the pad is marking the rotor as i brake. Im guessing that over time the whole pad will eventually bite the whole rotor?

RicK T

Some examples of normal rear Z51 contact area. The pads just cover the holes.

TRUOMEGA

Thanx for the info. I figured its just a matter of time before the whole surface of the brake pads meshes with the rotor. Just curious though... What do you mean when you say "flex in the caliper"?

TRUOMEGA

When i looked real close, the pads do not cover the bottom holes completely rather, the rear brake pads cover about 75% of lower holes leaving 25% of the hole exposed (That sounds a bit kinky doesn't it? )

VETFEVER

Yours are "normal" there won't be any more coverage as the break in....

RicK T

Just throwing this out. Another member had a similar issue and we advised him to drive it awhile to let everything "wear in" together. He did and it did. It all worked out fine after not many miles. Worth a try.

TRUOMEGA

cool. Thanx. Appreciate the info. Ill continue to monitor them for a while.

vettecdr07

TRUOMEGA. I just completed this very brake job this morning. I had the same problem. The pads do NOT bed properly. I took the whole assembly apart. I turns out a portion of the pad is riding a little higher toward the inside of the rotor. This is due to approx. a 2 mm lip that is not meant to be in contact with the pad. You can see it from your picture. So now only the inside of the pad and the outside of the pad are in contact with the rotor surface. I took the pads off and shaved about a 2 mm portion of the inside of the pad. Now the entire pad is flat on the rotor and bedding properly. Vastly impoving braking. I spoke to a forum member about this who, along with his wife races corvettes. He said he uses this shaving technique also. You'll see a 2 mm groove if you take off your pads. My fronts are fine and are bedding with out any modification. Just something to think about. When I attempted to bed the pads, the braking action was terrible. Also there are no pads that are specific to this rotor. I have checked far and wide. So save your self the touble. At anyrate just my .02 Cents. Hope this helps.

TRUOMEGA

Thanks for the response. I must have put around 200 miles since I installed them. I check them daily and as time progresses, the pad appears to be wearing in slowely. It still hasn't fully engulfed the rotor (the rear ones) but I can start seeing wear starting to occur on the lower portion of the rotor. Guess it just takes time. I'm guessing that in another 100 miles it should fully bed.
At this point, braking feels just the same as before I did the upgrade. Only issue I'm facing is i still hear squeaking when applying a certain amount of brake pressure. I can't figure out why. Used poziquiet ceramic pads, brand new rotors and that brake squeak prevention spray thingy. Perhaps you have advice on that for help. I'm gonna remove the caliper this month in order to paint it so I'll have access to whatever.
Thanks again for the heads up.

vettecdr07

What I did was use Permatex disk brake quiet. Dark Blue in color and works great. I also use Permatex disk brake lube. (part number 24110) CRC makes some excellent disk brake lube with Graphite in it and it is outstanding. It has some real staying power. but very messy. Don't for get to lube the guide pins and tourque to 30 ft lbs. The mounting brackets are tourqued to 130 ft lbs and the banjo bolts are 15 lbs. These tourques are important for proper movement. Inspect your pads for the wear I wrote about earlier. Good Luck. and hope this works for you.