A pinched brake line is believed to be the cause of the spectacular failure which put James Davison out of the Indianapolis 500.
Now, it has been reported that clamping force on the front brakes reached 279psi despite Davison not touching the brakes, and temperatures exceeded 1800 degrees Fahrenheit (1000 degrees Celsius).
Although only the right-hand side exploded, the left-hand side was also affected.
“We saw the temperature spike on telemetry,” DCR team manager Terry Brown recounted to North American publication Racer.
“James thought it was the motor and stayed in the gas when it wasn’t accelerating like he expected.
“On the brake calipers, the pistons have magnesium caps, and those reached the melting point first. From there, it was pretty spectacular – it exploded the middle of the wheel out.
“The right side was the one that went first, but the other side was pretty hot, too. It melted some things, but didn’t have a chance to go off like the other one.”
Davison was credited with just four laps and classified last of the 33 starters.