I recently purchased/installed new DBA (Z51) slotted rotors for front/rear with SS lines and GM ceramic pads & Z51 brackets...They work great! the problem is the rear pads don't cover the entire rotor and the rotor is starting to rust from lack of contact..The forum vendor who sold them said I should them and let the pads wear off the paint and I would be fine...after paying $900 for this set up and $1300 for the install??? It this normal when up grading rotor size from base size? Any suggestions?

 

I have seen this many times including when I upgraded to Z06 brakes. Give it a little time the thing that should have you worried is the $1,300 install for these parts.

 

Do you have an invoice for the rotors??? if so, confirm that you got the larger Z51 rotors.

What you see may be perfectly normal, but you can check easily by measuring your rotor diameter.

The rear rotor for a base C6 is 305mm/12inches, and the rear Z51 rotor is 330mm/13inches in diameter.

If you got the Z51 bracket to move the caliper out farther, but you have a base diameter rotor that is an inch less in diameter, then your pads will be missing a half inch of contact with the rotor firepath.

However, take a look (actually maybe a feel) at the top (the outer edge) of the pads. If they are even with the outer edge of the rotor then you're getting all the contact you can from them. If the pad is sticking above the outer edge of the rotor, then you've probably got the smaller base rotors.

Butt....I suspect that's just the way it is with your setup.

Now, about that 1300 bux to install them - Holy Crap!!! Too bad you don't live near Daytona - you could have come over to my driveway and we would have done it for free (well...about $10 for brake fluid, and a 6 pack) in 1-1/2 hours.

Bob

 

My stock Z51 rotors did this after the shop that turned them turned the inner unswept region. I just painted the whole rotor with BBQ grill high temp paint. The pads wore the paint off the swept path and the rest looks great. That was over a year ago and they stay looking fine.

 

Good advice

 

Anyone know why the Corvette manual says to create match marks on the rotor in respect to the hub when removing rotors for resurfacing?

Does the orientation of rotor-to-hub really matter with factory rotors and hubs?

I'm resurfacing rotors and installing Hawk ceramic pads on my 2005 Z51. My index or match marks disappeared while cleaning the mating surfaces. I won't even be able to tell which side of the car the rotors came from.

 

I assume/hope the $1300 was including the $900 for parts?

 

I agree but I dont read it that way. Looks like $2200 total. Wow!

 

I did not know about this. When I did my rotors I kept track of which side they went on, but I did no such indexing and LIVED TO TELL ABOUT IT!!!

I'm guessing you will be fine.

 

Maybe it has to do with run-out measurments during vehicle assembly. I can't imagine why the rotors should be indexed to the original orientation during a routine brake job.

Hopefully the original Z51 rotors are not directional. If they are (directional) I suppose I'll be able to tell by looking at them as to which rotor came from which side.

 

The $1300 was for install of ss brake lines, rotors and GM ceramic pads by my local chevy dealer in Cary NC! The only parts the dealer provided were the pads & brake fluid...I paid $400 for the rotors, $350 for the lines and Z51 brackets form a forum vender...I originally paid $900 but returned the brake fluid and Hawk pads and went with the GM stuff instead...all is good...came out great!

 

Many of the aftermarket pads I've seen do not cover the same lateral area stock pads do, and that'd be totally unacceptable to me. I can understand this going from padlets to one-piece pads, but not when replacing a single pad with another. Maybe copyright infringement??? I'd like to change to ceramics in the future on my new GS, but only if they're identical in actual swept area (no more no less). And actually better than stock, since with black wheels, I'm not that annoyed by the dust. And yes, they'd have to be padlets, to keep the brakes the way the manufacturer intended. Good day.

 

Wait just a minute....the the $1300 was for labor to install a set of brakes?!!!?....Boy oh boy, they saw you coming a mile away!

 

Your pic is a normal wear pattern, paint it and be done

 

No kidding!!!!! I hope $1,300 wasn't just for the install as I did mine in about 3 hours including a flushing the brake fluid. That was taking my time.

 

WOW!!! That was really expensive for the dealer to charge, that could have been close to the purchase price of longtube headers.

 

After my guy cleaned up my rotors I ended up with 0.008" LRO (lateral run-out) on all four rotors. I guess the guy's lathe was tired and few shops have a dial indicator near the brake lathe.

The Corvette manual says 0.002" is maximum allowable LRO and the manual suggests using Hub Correction Plates (available in 0.003" 0.006" and 0.009") which are illustrated in the manual. Since my rotors are not thick enough for another cut with an on-car lathe, I'm looking for someone who has tried the Hub Correction Plates <=> http://www.brakealign.com/pages/video.html.

If I opt to replace the rotors, who makes the zinc plated rotors that are slotted and cross-drilled? Are they as good or better than the OEM cross-drilled rotors? I know the track guys don't like cross-drilled rotors but my car probably will see minimal track time and I am weary of the rusty water dripping on the chrome wheels. I converted to Hawk ceramic pads and my car is on jack stands until I get the correction plates or new rotors. Tire Rack has no rotors in stock for my 2005 Z51.

I'm open for suggestions regarding new rotors but would rather try the correction plates if someone has personal experience with the plates. The instructional video at www.brakealign.com looks like this is acceptable technology as long as LRO is not over 0.009". Stacking correction plates is not allowed.

Most importantly, I do not wish to downgrade my rotors with a brand that has a hot sales pitch but is lacking in total metal, weight, vanes, and other features that most folks would never notice.

My hubs are spot-on with zero runout. Likewise with the inside (painted) area of the rotor as seen in the last photo. I did not measure LRO prior to removing the rotors but I see no possible cause for 0.008" LRO other than a worn out brake lathe - though I lost my Sharpie match marks while cleaning the parts.