NASCAR Cup Series competitors who have been advocating for the opportunity to change brake rotors and pads after practice and qualifying have finally been rewarded for their efforts starting at Phoenix.
This weekend, teams are allowed to replace the front brake rotors and pads after Saturday’s practice and qualifying sessions at the one-mile track. No other brake system components can be changed. The teams may inspect the rear rotors during Sunday’s pre-race adjustments. NASCAR says any rotor issues found at that time will be managed on a case-by-case basis.
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Denny Hamlin (#11) and Chase Briscoe at World Wide Technology in August both dealt with brake problems.
Brake pad and rotor issues came to light in August at Iowa when Joe Gibbs Racing teammates Chase Briscoe and Denny Hamlin experienced brake issues in practice. NASCAR allowed the drivers’ crews to change the brake rotors but not the brake pads. The brake issues continued during the race. After the Iowa race, an exhausted Hamlin said he would retire at the end of the year if he had to deal with that situation every week. Briscoe described his brakes during the race as a “little odd.”
Then in September at World Wide Technology Raceway, exploding brake rotors translated into a disastrous day for four Chase contenders. Ryan Blaney, Chase Elliott, and Chris Buescher were eliminated from the event when they each had a brake rotor explode on their cars. Elliott collected Chase Briscoe in his accident. Zane Smith also had a brake rotor explode in that race as did Noah Gragson.
Buescher said the fact Blaney’s right-front brake rotor exploded on the front stretch before he started braking into the turn was “strange in general.” However, he noted a few days after the race that there were a “handful of common denominators across the failures in the garage.” Buescher noted problems develop when the brakes become “super-hot” and then begin cooling during a red flag.
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The front brake rotor glows on the race car of Austin Hill at Nashville in May.
“I’ve had issues of similar sorts in my ARCA days, and I learned from those way back then that you don’t just sit there and stay put. You have to keep moving forward, try and rotate hot spots basically on the entire system—tire, brakes, and all,” Buescher said.
Under the current NASCAR rule book, AP Racing Limited supplies the brake rotors and calipers while the teams are responsible for the brake pads. The teams aren’t allowed to machine brake calipers for hardness testing. That must be done by the single source vendor or its designated distributor. All requests must be submitted and approved through the NASCAR Repair Submission Portal.
Three brake-cooling assemblies may be used on the front brake and a maximum of two on the rear brake. Liquid or gas cooling of the brakes isn’t permitted. Also, a brake cooling assembly configured to direct air somewhere other than for cooling a brake isn’t permitted.
A North Carolina native, Deb Williams is an award-winning motorsports journalist who is in her fourth decade covering auto racing. In addition to covering the sport for United Press International, she has written motorsports articles for several newspapers, magazines and websites including espnW.com, USA Today, and The Charlotte Observer. Her awards include the American Motorsports Media Award of Excellence, two-time National Motorsports Press Association writer of the year, and two-time recipient of the Russ Catlin award. She also has won an award in the North Carolina Press Association’s sports feature category. During her career, Deb has been managing editor of GT Motorsports magazine and was with Winston Cup Scene and NASCAR Winston Cup Scene for 18 years, serving as the publication’s editor for 10 years. In 2024 she was inducted into the NMPA Hall of Fame.