Denny Hamlin recently gave a detailed account of the brake failure that made his Sunday afternoon Iowa Speedway so difficult. He revealed that his No. 11 Toyota was operating with extremely inconsistent braking performance for much of the afternoon.
The situation was especially concerning because the brakes did not gradually lose effectiveness; instead, according to the JGR ace, they would suddenly disappear when the heat built up.
“Well, because of what I had to do in the car to make it first not wreck on corner entry, and it’s a little bit of tech talk, but it’s like I don’t know whether the brake pads are going to grab the rotors or not,” Hamlin explained on the latest episode of his podcast, Actions Detrimental.
“And it just depends on how much they get knocked back on the straightaway, and it depends on how hot they are at the time.”
The championship leader said the inconsistency was so extreme that his car sometimes had virtually no braking ability and at other moments recovered enough pressure to become somewhat manageable.
“So, I just had no brakes for probably, I would say, 0% of the time, never; 10% of the time; 20% of the time, 50% brakes 60% of the time, and I had full brakes for, if the math adds up, 20ish% of the time,” Hamlin said.
The biggest problem came when the brakes overheated. The pedal could suddenly drop completely to the floor, leaving Hamlin to deal with his No. 11 Toyota, which was difficult to slow down as he approached the corners.
“I’d have decent brakes to where the pedal was good, but the minute it got any sort of heat to it, they went away,” Hamlin said. “And when they went away, they went away right off the bat. So, it just didn’t slowly work its way down. The pedal then would just go all the way to the floor.”
That left Hamlin constantly trying to rebuild brake pressure on the straightaways. Pumping the pedal sometimes helped, but the effort itself could generate more heat and make the situation even less predictable.
As he put it, “So then, now every straightaway I’m trying to pump these things up. Well, the pumping worked for some of the time to get me like to the 50% break, but if they got really hot sometimes because I’m pumping them down the straightaway, it would go all the way to the floor, and then I’d have the 10% break.”
During the whole race, Hamlin had to approach each corner without knowing exactly how much stopping power would be available when he reached it.
Hamlin first encountered the issue during Saturday practice, when his brake pedal repeatedly went to the floor after just a few laps. He said he stopped running because continuing under those conditions during practice made little sense.
Crew chief Chris Gayle had experimented with a setup that leaned on 23XI Racing, which had shown stronger form at Iowa than Hamlin’s in previous races.
The team ultimately believed a bad batch of brake pads was responsible, because the same combination had been used successfully in numerous races. Yet NASCAR’s rules limited what could be changed before the race, preventing Hamlin’s team from simply replacing the pads.
Meanwhile, Gayle changed the brake cooling ducts to direct more air toward the brakes. Because the adjustment was made after qualifying, NASCAR sent Hamlin’s No. 11 Toyota to the rear for the start.
The cooling change failed to provide the solution the team wanted. Hamlin reported that his brakes were gone by Lap 3, leaving him facing the entire 350-lap race with the problem still hanging over him.
Yet the team managed to adapt the car enough for Hamlin to continue racing. The adjustments could not specifically restore normal braking performance, but they gave him a way to manipulate the car and work around its biggest weakness.
Starting from the rear and fighting unpredictable brakes throughout the afternoon, he worked his way forward to finish in the top five, while teammate Chase Briscoe came home sixth.
The finish also preserved Hamlin’s position at the top of the regular-season standings, with his advantage growing to 103 points over Ty Gibbs, who won the Iowa Corn 350 race, with three races remaining before the playoffs.
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