When should I replace my brake rotors?

Our AP Racing J Hook Discs sometimes last so long that our clients get a little nervous about whether or not to replace them. We've had this happen on several occasions over the past few years, and we always love seeing this type of feedback. Most of these owners are used to their OEM discs, or our competitors' discs, cracking or wearing out very quickly under heavy track use. They're always shocked by the abuse that the AP Racing J Hooks can sustain. Below is an email from a conscientious Porsche GT4 owner who recently had this experience:

"I've been happily running the Essex/AP Racing rotor on my Cayman GT4 for a few years now. I've also read your "When Should I Replace My Brake Discs?" article. The reason I'm reaching out is that my current front rotors have seen 23 days at Circuit of the Americas running in the advanced student and instructor run groups -- and yet they only look like maybe photo #3 or 4 in your article, i.e. one or two steps before the "patch of arid ground" stage photo. I see the note about checking for terminal cracks, particularly ones that might be hiding on the inside, but I don't see any of those.

I'm not the type that insists on squeezing every last penny of value out of what I buy -- especially when it comes to brake equipment on a track car! -- but I also don't want to write off a huge chunk of value senselessly. My dilemma is that 23 track days intuitively seems like a lot for a single set of rotors, and yet your article seems to suggest that they may yet have a fair amount of life in them. If that's the case, can you give me a very general idea of how much longer I might be able to safely run these rotors based on their current appearance after 23 track days, assuming no terminal cracks appear unexpectedly soon?”

We always encourage our clients to contact us if they're unsure about the condition of their brakes. As a rule of thumb, if you're ever uncomfortable or unsure about the condition of your brakes, don't run them. Snap a few pics on your phone, shoot them over to us, and we'll be happy to take give our opinion on their condition. It's why we are here!

Below are some related blog posts about the incredible longevity of AP Racing J Hook Discs:

• "When is it time to replace my brake discs?"
  
• Price vs. Value and Miles per Dollar
• 991 GT3 owner gets 70+ days out of his AP Racing J Hook Discs
• AP Racing Competition Brake Kit five year review
• Four Years & 50,000 of Abuse on Our Smallest AP Racing Kit!