Toto Wolff says that high temperatures caused the brake-by-wire failures on the two Mercedes cars in the closing stages of the Bahrain Grand Prix.
Nico Rosberg, who battled with overrating brakes throughout the race, lost second place on the penultimate lap after he ran straight on at Turn 1, allowing Kimi Raikkonen by.
Lewis Hamilton led comfortably throughout the race, but reported a similar failure in the closing stages and was forced to nurse his car home, ahead of an onrushing Raikkonen.
“We saw very hot brakes on Nico’s car in traffic, following Kimi and Sebastian first, and then lots of fighting and hard braking,” Wolff said.
“We monitored that, then at the end with the backmarkers and lapping cars those brake temperatures went through the roof, and we had a brake by wire failure on both cars, in the same corner.
“It was on the hard braking on the straight, the temperatures went sky high, and when that happens the brake by wire switches into the conventional system, and then you are without weapons to defend with.
“You can’t do anything if the brake-by-wire collapses or fails and it goes to conventional, the pedal becomes long and the car doesn’t stop any more. This what happens to Nico.
Wolff admits the team was aware the issue could arise after it changed the set-up of both cars.
“It’s set-up issues,” he explained. “We knew the changes we made on the car were compromising a little bit brake temperatures, so we knew what we were doing.
“But then it was a hard race, we had lots of overtaking, especially on Nico’s side. And then both cars struggled to make it through some of the backmarkers at the end of the race.
“You follow another car or you follow a couple of cars the air stream collapses, and this is why he made the brakes hot.
“On Nico’s car the brake failure didn’t come as a surprise, we saw high temperatures. On Lewis’s car it was a bit of a surprise, and it must have been linked to the fact that he gave it a gentle push seeing Kimi, and making his way through backmarker traffic.”
Image courtesy of Daimler