Red Bull Racing has revealed that Sebastian Vettel's brake problem in the Spanish Grand Prix was caused by a freak split of the front-left disc.
Vettel was forced to slow in the closing stages of the Barcelona event with brake issues, but he was able to nurse his RB6 home to take third place.
Investigations undertaken by Red Bull Racing after the event show that the issue was caused by a front left disc failure - something the team had not experienced before.
"The problem was quite bizarre as basically the brake on the left hand side stopped working completely and the disc effectively split in half, straight down the middle of the spline," explained Red Bull Racing team principal Christian Horner.
"You have just got a spacer in there and so he had only got three brakes, so all the bias was towards the rear and he was using mainly the aerodynamics to stop the car and built some huge margin into his braking zones.
"With having fitted the option tyre at the end of the race on relatively light fuel load he actually did a purple sector in the middle sector with three brakes.
"It was ironic as I was joking with Adrian (Newey) the night before about his first car being an Austin Allegro which only had three brake discs and unfortunately in the race Sebastian's car turned out to be similar to that. But he managed it incredibly well and to get the car home in third place was a valuable and brave performance by him."