Toto Wolff says high temperatures led to brake-by-wire failures on both Mercedes cars during the Bahrain Grand Prix.
Nico Rosberg was warned about his brakes early in the race, but pulled two robust overtaking moves on Sebastian Vettel under braking into Turn 1. However, the problem worsened on the penultimate lap as Rosberg was forced wide at the same corner, allowing Kimi Raikkonen through in to second place. Lewis Hamilton then reported a similar problem on his final lap as he was forced to nurse his car home, seeing Raikkonen cut his lead by over three seconds.
Explaining the problem, Wolff says Mercedes thought it had managed the issue successfully after Rosberg had overtaken Vettel.
“We saw very hot brakes on Nico’s car in traffic following Sebastian before with lots of hard braking,” Wolff said. “Then we monitored that, but with the backmarkers and the lapping cars those brake temperatures went through the roof and we had a brake-by-wire failure on both cars in the same corner.
“Leading into the last lap it was under hard braking on the straight that 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.”
And Wolff admits Mercedes was aware the issue could arise as a result of the set-up direction the team took during the weekend.
“It is set-up issues and we knew the changes we made on the car were compromising a little bit the brake temperatures. We knew what we were doing. But then it was a hard race with lots of overtaking, especially in Nico’s side and then both cars struggled to make it through the backmarkers at the end of the race. The minute you follow another car or a couple of cars, the airstream collapses and this is why it made the brakes go.”