Pad thickness, when do you replace them for tracking?
 

I'm fairly new to tracking my ZL1, did 4 sessions last year and drive pretty aggressively in general. I'm taking it in to have it serviced and the brakes checked.

How low do you go on your pad thickness before replacing them? Anyone happen to know the stock thickness when new?

Thanks!

I let my pads get pretty close to the wear bar and then swapped them. It all depends on which track you’re at and driving style but I wouldn’t let them get too low. I use a digital caliper to measure my pads before and after to get a baseline of how much pad I use so I have a good estimate of how much life is left in them. It’s been a while since I’ve pulled my pads but I believe the stock pads are .780”.

My rule of thumb - replace the pads when the the material is less than the backing plate's thickness.

At least some track day organizations want you to start the day out with at least 50% friction material thickness remaining. Not sure what your pads start out at, but I'd bet that under that guideline 1/4" = pass, 3/16" = iffy, and 1/8" = fail.

I've let mine get down to just under 0.20" at the end of an event (against about the same thickness backing plate). Just measured an old set I had laying around.



Norm

I'm definitley in the minority here. I use pads until there is VERY little material remaining. That being said, I keep a very close eye on them and always have replacement pads ready anytime I'm planning on tracking the car and pads are less than 50%.

Brake pads for our cars cost big $, so I want to get the most out of them. The answer to the OP's question is also very dependent on if you are comfortable switching out pads yourself (especially at the track). If I wasn't doing the pad swap myself, I also would swap them out early.

Thanks for the replies.

I'd like to learn how to swap my own pads at some point as I assume I'll be changing them often with this new addiction. Not sure how to learn it, sounds and looks easy enough but I also need to trust I did it right at these life or death speeds.

Pads on our car are one of the easier things to do. Matt has a pad and rotor replacement video that is a good reference.

https://youtu.be/43YbNX_RqL0

Here's a video on the 6 pot Brembo which has an extra bolt. Not necessarily the best methods are used in this one. Lots of goods video on Brembo pad change on youtube. Looks so easy I think I can even do it.

https://www.youtube.com/watch?v=d4sfegIXamY

Thanks for the videos, it does look pretty easy. Worth a shot.

It also depends upon the pad compound that you are using and temperature range you are using them in. When combined with low temperature street operation and 26 track hours my big brake kit with full on endurance race pads lost nearly as much rotor thickness as pad thickness. That's due in part to the low temperature operation but a serious race pad will likely bite into the rotor nearly as much as the rotor bites into them lol.

6th Gen ZL1 stock brake pads are between 9mm and 10mm when new (front and rear are approximately the same thickness).

Once the pads are 5mm or below, I replace them.

Front:
Attachment 931002

Rear:
Attachment 931003

When the light goes off change them

That's not a good idea. The light is based on fluid level in the reservoir, which has no direct relation to pad thickness... Sure, if you're not tracking your car and you never top off the fluid level, it's a decent indicator for normal break use. However, when we start tracking and changing fluid, topping it off, etc., everything is different.