Red Bull team principal Christian Horner says the team is investigating Daniel Ricciardo's race-ending brake failure in the Russian Grand Prix to determine the root-cause of the problem.
Ricciardo was seventh at the restart following an early safety car period in Sochi when smoke started pouring from the right rear brake on his RB13, ultimately causing him to retire from the race. Red Bull teammate Max Verstappen crashed out of last month's Bahrain Grand Prix after suffering a rear brake problem, though Horner insists early signs suggest Ricciardo's issue was not related to Verstappen's.
"It was a real disappointment to lose Daniel early in the race with a right rear brake issue, straight after the safety car restart," he said.