jvp

Yes. The adhesive is out-gassing from the pad. It causes a pocket of air to form between the pad and the rotor.

jas

Chris_B

Again, not so much off-gassing with these pads. And, again, these types of pads are post-cured (typically 800+°F for 12+ hours), so the binders are all but completely cooked out already. Off-gassing is nearly all done in the oven before they see paint.

This is almost all due to a lack of proper transfer layer on the rotors. Burnishing takes off the high spots (much like running in a cam and lifters), while bedding lays down the transfer layer after the surfaces are fully mated. I'm not sure why I'm trying to convince you of what I work with on a daily basis, so I'll just stop this point right here. Believe whatever you'd like to.

The cost of burnishing and bedding on the vehicle, in reality, is higher. I have experienced this myself in CCM conversions that I have been directly involved in. Reputations do have a cost and so do tires, fuel and potential tickets. The pad material consumed during burnishing and initial bed-in on a computer controlled dyno is usually less than .001", so no extra material is needed. It usually costs the pad manufacturer less to make a thicker pad (less time required on the grinding machine), yet they typically charge more for it.

If it were my car, I'd easily take the minor loss in pad volume for brakes that worked the first time out. Bedding iron rotors on the car is relatively easy (although few do it -- and do it correctly). Bedding CCM rotors is asking the customer for a bit too much, in my opinion. The method GM has written is not as good as the best method, in which you need to maintain certain negative g-loads of the car while driving during each phase. Since most people won't have that equipment handy, the next best it to write it up like they did, which somewhat estimates the negative g method.

You are correct. Bronze pins are not pad rivets, which are generally made of steel. The pins are part of yet another friction retention scheme (retention wire), which is a little less desirable than the NRS method. Raybestos still uses the wire on some of their race pads as a tertiary safety device, but I had been told by Pagid they had all but dropped it. Interesting.

marktsmith

I just completed the burnishing process. I did get a soft pedal around the 40th repetition, but it recovered quickly (next stop). I then got the soft pedal one more time before the 50th repetition. Got plenty of smoke, got a "rear tire air pressure too high" message on the message center. After the cool down drive, I checked the pads. There was a definite white edge on one front pad, a smaller white edge on the other front pad, but no visible white edge on either rear brake pad ? Not much interested in doing the process again ?

Mark.

Dr.Ron

I got my car used. I doubt the brakes were bedded in.
I have though run an HPDE day. I assume the pads were bedded in doing that. \Is it still recommended to do the street bed in process??
No white line on the pads seen by the way..

Ron

phipp85

I would think if you did an HPDE day and didn't get any fade they have been burnished, I could be wrong though. I don't know how hard you are on the brakes. I guess it's possible to do a track day with unburnished brakes and get no fade, but you sure would have to be real easy on the brakes.

I would just do the burnishing procedure myself, then you know it's been done.

Dr.Ron

I'm not real hard on them as I'm out there to have fun, not to try to set any records.

I did feel some fade in my 1st session coming off the front straight, but it possibly could have been the ABS kicking in too. I switched to competitive driving mode afterwards and it seemed to have gone away for the most part, except 1 other time I think.

ace32x

curious i picked my z up used obv, its an 09 with original rotors and pads. im assuming if it was just cruised on the street all its life and not tracked the burnishing procedure hasnt been completed and normal wear and tear isnt enough to burn off the adhesive? am i right to assume this and go ahead and follow through with the burnishing procedure

Gary '09 C6

^ IMO, better late than never...

but, if you can see a thin white line around the edge of the pad where it contacts the rotor,
it's likely the burnishing has already been done. There are some pictures at the beginning of
this thread showing what the pad will look like...

ace32x

good point, i wasnt sure if that residue would still be there down the road if it was completed before.

Bigbucks

It certainly appears that Chris is correct, and that a transfer layer is required to both protect and enhance CCM rotors. Don't take my word for it, have a read here...

http://documents.clubexpress.com/doc...l9IpKvdMH3A%3d

DebRedZR1

What was the verdict if they have never been done? Say car has 12K miles, heading to more high speed events, should they be done, owners manual says to do them when new, what about after the fact?

marktsmith

It is my understanding from reading other messages on the Forum that it is OK to perform burnishing at any time. Some even suggested doing it a second time after some mileage. Look for the little white shadowing on your pads that should be present after the burnishing process. The shadowing will be right against the rotor.

NYOverlord

Great Post Jason! We all benefit greatly due to your time and effort explaining this to us.

Dr.Ron

Finally had to replace the front pads. I went out last night around midnight & did the burnishing procedure. I'll say this, if I had to do 3-4 more stops I would have had to pull over and lose my dinner! I was not right in the stomach for around 45 minutes. lol

I only got the right pad with the white ash. The left pad didn't seem to have the white, but no way I can go do that again!

Ron

SlowZo6

Hey guys I have a question.

I took my 2013 ZR1 out last night and did the brake burnishing to the pads. 50 stops from 60 to 0 going from 1st to 4th, (didn't wanna make to much noise my car is loud with 800rwhp). It took me about 12 minuets to do it. Unfortunately I live right off a main route so there is always some type of traffic even at 1:30am.

This is the same stopping method I used on my 2010 ZR1 and when I got done I noticed I had the white ash around my pads. Now on my 2013 I have ZERO white ash on any of the pads.


I know the pads got super hot, they where gassing out pretty bad and I could smell it. I did experience brake fade and the pedal even became spongy then came back. (These are all the same symptoms I had experienced on my last ZR1) the rims where super dirty I cannot tell if they discolored due to the rims being gloss black but on my 2010 ZR1 with chrome rims they sure did. I drove for a good 15 minuets after burnishing to let the pads and rotors cool down.

So basically my question is are the pads done being burnishing? Or do I need to do this all over again?

Gary '09 C6

From the details you described, it sounds like you did the burnishing properly. My only thought is maybe there was
a change in the (assumed) OEM pad material which could result in less visible "white ash" residue post-burnishing ?

mfain

Here's something interesting in the "for what it's worth" category. I just read the 2016 Viper ACR owner's manual, including their recommendations for burnishing the CCBs - virtually the same Brembos that are on the ZR1 and C6Z/Z07. They use a different schedule and warn not to come to a complete stop because it will cause transfer of material to the rotor that can cause a subsequent vibration. Certainly a different procedure than GM recommends. Sorry if this is a repeat of information contained earlier in this thread.

Pappy

Mamandoli

Finished my burnishing last weekend. CCB rotors 2016 Z06.
I was stressing about it for a month while I finished properly breaking the car. A lot of what if's..... Well piece of cake. I think 12 minutes. I even had my wife with me counting. Didn't get car sick and put my heater on re circulation so not much brake smoke entered the car. Had to make a U turn because I ran out of straight away. I was about at the 30th stop and the front were really smoking. Properly cooled them off at 50 stops and when I got home inspected them and the pads had a nice white color close to the rotor. Well off the the track in a couple weeks.

Widgeon5

Will the caliper paint (red in my case) be damaged by the burnishing procedure?

Batman 357

I'm looking for a place to do the burnishing now. How far did you have to go to get in your 50 braking events.