[GarnetRedJuan]

I think this might be an easy one for you all.

The question is, after 1 set of OE pads and two of z26 pads and getting a shudder, in the experience of this forum, is the stock pad aggressive enough to clean the rotor up after some driving, or should I plan on a manual clean or rotor replacement? Also, if I run the new pads on the old rotors and the shudder doesn't go away, will the pads be trashed and have to get new ones with new rotors? This stuff isn't the cheapest to take chances on.

Since owning the car since new in 2017 and 40k miles later, I have gone through one set of OE pads and two sets of the Powerstop z26. I loved the stock pads but the z26 left a lot to be desired. I do think they stop ok enough and the dust is almost non existent, but I did not like how fast they faded after one or two spirited pulls and brake events just on the now occasional drives. The second set of pads still have 50% life but will fade out with one harding brake to the point where they become dangerous. They have also created a shudder from deposits with anything more than just normal braking. Long story short, not for me and I am going to go back to stock.

Thank you all.

[Gunkk]

Here's what I do with a brake vibration or change pads/rotors on one of my cars:

1. Gloves on (keeps skin oil and sweat off the friction surfaces, and hands clean)
2. Remove the pads.
3. For vibrations, measure runout on the rotors with a dial gauge. If <0.001"-0.002" on the outer edge of the swept area then the vibration shouldn't be the rotor or hub. If >0.002" remove the caliper and rotor and check the wheel hub for runout. If it's more than 0.0005" it is likely bent. Replace warped/bent components as appropriate.
4. Sand all friction surfaces on the pads and rotors with 600-800 grit sandpaper to remove the burnished surface layer.
5. Clean the pads and rotors with brake cleaner and paper towels. I'm a CRC red can kinda guy, but green works too. Swap out paper towels frequently to keep the binder from getting back on the rotors. Repeat on the rotors until no more residue comes off the brake disc, and surface rust barely starts to form (metal sheen goes a dull after a few seconds).
6. If gloves are dirty/greasy, swap to new. Reassemble without touching the friction surfaces at all -- like you would a headlight bulb -- and it won't squeak.
7. Seat the lugs by hand, torque wrench to spec.
8. Bed in the brakes to replace the binder transfer layer and confirm proper operation.

Sanding and using brake cleaner on the friction surfaces removes the binder transfer layer including uneven sections of pad transfer that cause stick-slip vibrations under light braking at higher speeds. Binder stick-slip can make you think stuff is warped when it's not.

If your runout was perfect and the car still vibrates under braking after bedding them in, inspect your rotors for variation in finish across the disc. If they're perfect, then check for wheel and tire defects.

Originally Posted by GarnetRedJuan

I did not like how fast they faded after one or two spirited pulls and brake events just on the now occasional drives.

If you haven't bled the brakes or changed the fluid, do so. Wet fluid in the pistons might fade on you prematurely.

[cdb95z28]

Pads have two friction modes, abrasive friction (cold) and adherent friction (hot). The OE pads may have enough cold abrasive friction to clean up the rotors. Some guys have complained about noise when street driving. This usually is a sign of all transfer layer being wiped off due to being in abrasive mode. Keep the temps down. Just do light to moderate braking. Keep the applications short in order to not build too much heat. I don't think you'll hurt the new pads if you don't have success, so long as you didn't outright cook them, for some reason, beyond even what a track day would. It may take time because the new pads have to bed in to the rotor surface.

An aggressive race pad would clean them up but it's unreasonable to purchase them just for that use.

I've used this course hone multiple times over the years on various vehicles with success. I haven't used it in a while because I have moved away from low temp, usually ceramic, pad materials on all my vehicles. I try to use semi metallics. Yeah, dirty! But the saying is "A dustless pad is a stopless pad". Not necessarily true but good pads will have some levels of dirt. The OE Ferodo HP1000 pad is a very good dual purpose pad.

https://www.amazon.com/dp/B007INTEMC...m?ie=UTF8&th=1

You would have to remove the rotor to do use it on the back side. If the rotor is well within the minimum thickness and has no deep scoring I would reuse. In very rare instances, a rotor can be damaged from repeated heavy use during the shudder which 99.5% of the time is due to uneven pad transfer layer. The high spots can overheat the cast iron to the point that the cast iron develops a super hard area that cannot be machined out.

[dpevans]

First thing I would do is remove the rotor and check thickness, not sure what your RPO code is but J6M discard is 34mm. If you tell me your RPO code I can look up your min thickness. Thickness variation according to the manual is .001. Is the hat firmly attached to the rotor ring, does it feel loose, you might need new hardware but unlikely. Don't mess with nuts those are crimp nuts good for only one use. Clean the wheel bearing surface and back of the rotor hat surface then put the rotor back on and check run out, manual say .004 is acceptable. One suggestion, purchase a tap for the caliper bolts, the caliper is aluminum and easy to strip and cross thread unless you tap the holes. Tap size is 14x2. Clean the caliper bolts real good and use blue loctite during final assembly. If you are using a street pad the manual burnish procedure is 20 stops without engaging ABS from 30 MPH. Track pads I go 50-70mph slow down to 20 with .5 mile in between events and do it 25 times then drive for 15-20 minutes without using the brakes. If you do decide to buy new rotor rings DM me and I can help you and save you some money.

[donaldp]

I had the same issue early on with my 2017 ZL1 stock pads. The advice I received on the forum was as follows:

Accelerate to 80 MPH and slam on the brakes as hard as possible without activating ABS braking.
Repeat this three times.

Amazingly, by shudder was gone and has never returned. I recently replaced my stock pads at 85,000 miles with more stock pads. I don't like the brake dust, but the braking power is way more important to me.

Try this easy process with stock pads and report back

[m6-lt1]

Originally Posted by cdb95z28

Pads have two friction modes, abrasive friction (cold) and adherent friction (hot). The OE pads may have enough cold abrasive friction to clean up the rotors. Some guys have complained about noise when street driving. This usually is a sign of all transfer layer being wiped off due to being in abrasive mode. Keep the temps down. Just do light to moderate braking. Keep the applications short in order to not build too much heat. I don't think you'll hurt the new pads if you don't have success, so long as you didn't outright cook them, for some reason, beyond even what a track day would. It may take time because the new pads have to bed in to the rotor surface.

An aggressive race pad would clean them up but it's unreasonable to purchase them just for that use.

I've used this course hone multiple times over the years on various vehicles with success. I haven't used it in a while because I have moved away from low temp, usually ceramic, pad materials on all my vehicles. I try to use semi metallics. Yeah, dirty! But the saying is "A dustless pad is a stopless pad". Not necessarily true but good pads will have some levels of dirt. The OE Ferodo HP1000 pad is a very good dual purpose pad.

https://www.amazon.com/dp/B007INTEMC...m?ie=UTF8&th=1

You would have to remove the rotor to do use it on the back side. If the rotor is well within the minimum thickness and has no deep scoring I would reuse. In very rare instances, a rotor can be damaged from repeated heavy use during the shudder which 99.5% of the time is due to uneven pad transfer layer. The high spots can overheat the cast iron to the point that the cast iron develops a super hard area that cannot be machined out.

I used the tool this guy said and so far (knock on wood) it’s worked. Only thing is I recommend LEAVING the rotor on the car, removing the pads and spinning the rotor by hand while using the tool. I believe it’s much more effective this way and possibly safer (not sure how aggressive the tool actually is)? Watch this video below as it shows the steps I described.

https://youtu.be/XpK_dA68_T0?si=0T6aK_iujbkAQ4wo

[GarnetRedJuan]

Thanks for all the information y'all.

Walmart actually has the rotors heavily discounted right now. I ended up ordering those and they came in yesterday. I still haven't decided if will replace them or not but there's a long return window.

Regardless 550 bucks for the two front rotors after 8 years doesn't sound too bad all things considered.
https://www.walmart.com/ip/seort/795175688

[arpad_m]

Originally Posted by GarnetRedJuan

Thanks for all the information y'all.

Walmart actually has the rotors heavily discounted right now. I ended up ordering those and they came in yesterday. I still haven't decided if will replace them or not but there's a long return window.

Regardless 550 bucks for the two front rotors after 8 years doesn't sound too bad all things considered.
https://www.walmart.com/ip/seort/795175688

Even cheaper at amazon, $227... price fluctuations are unbelievable, I bought my SS 1LE rotors for $400+ each, and these ZL1 units are even larger.

[cdb95z28]

Originally Posted by GarnetRedJuan

Thanks for all the information y'all.

Walmart actually has the rotors heavily discounted right now. I ended up ordering those and they came in yesterday. I still haven't decided if will replace them or not but there's a long return window.

Regardless 550 bucks for the two front rotors after 8 years doesn't sound too bad all things considered.
https://www.walmart.com/ip/seort/795175688

Originally Posted by arpad_m

Even cheaper at amazon, $227... price fluctiations are unbelievable, I bought my SS 1LE rotors for $400+ each, and these ZL1 units are even larger.

I bought those same rotors back in early May. Great price for sure.