Toro Rosso's Brendon Hartley and Pierre Gasly were forced to retire in the opening laps of the Russian Grand Prix after suffering overheating brakes on both cars.
As both drivers attempted to go to battle with their nearest rivals, they eventually found themselves spinning off the circuit due to blocked pistons which led to brake fluid overheating and which caused their brake pedals to go long.
Team principal Franz Tost has expressed his disappoint at the result of the race and said the team will conduct a full investigation into the problem.
"It was a frustrating Sunday for Toro Rosso as both cars had to retire," said Tost. "For whatever reason, we ended up with very hot front brakes and one piston in the calipers got stuck.
"This caused the overheating of the brake fluid and a long pedal. Therefore, we called the drivers to come to the garage.
"Obviously, being in Parc Fermé conditions, we didn’t change anything from yesterday, so we need to investigate further what the reason is. The positive side of this weekend is Honda’s new upgraded engine which is a big improvement.
"Now we are focusing on preparing everything for Suzuka where we hopefully will have a much better race."
Hartley believed he got a good start to the race but his progress was quickly hampered by a spin caused by the brake issue unbeknownst to him at the time, he made a stop to try and go a different route on strategy but the brakes continued to go to the floor and was forced to park the car.
"I had a good start and passed Pierre before Turn 5," added the Kiwi. "I was attacking the McLaren when the brake pedal went long.
"I reported it on the radio and then made our planned pit stop. We were going to try and be a bit cheeky with the strategy and do almost a full race on the Softs, we had great tyre life and pace and think it would have worked.
"However, once I left the pits the pedal went completely to the floor, the rears locked and the car spun. The same happened across both cars at the same moment so I’m sure the team will quickly diagnose and sort it out for the next race."
Gasly admits he felt the problem right from the very start of the race and deteriorated very quickly before he spun going into Turn 4.
He added: "Since the start of the race I had a really strange feeling with the brake pedal, it went pretty long and got worse very quickly. Then, on the third lap at Turn 4, I braked and the pedal went completely flat, so we lost all the front brakes and had to retire the car.
"We need to have a look at the data to see exactly what happened, but it’s just a shame to see both cars retire so early in the race."
