The Haas Formula 1 team endured another difficult day of practice ahead of the Russian Grand Prix as drivers Romain Grosjean and Kevin Magnussen suffered more brake issues despite changing supplier.
Haas confirmed on Thursday that it would be switching from Brembo to Carbon Industrie brakes, having suffered problems throughout its 14-month stint in F1.
Despite enjoying a positive test in Bahrain with Carbon Industrie parts last week, both Grosjean and Magnussen struggled with their brakes in FP1 and FP2 at the Sochi Autodrom on Friday.
Grosjean finished FP2 14th-fastest, with Magnussen breaking into the top 10, charging to ninth place in the VF-17 car.
“We’ve got very little grip. We’re really struggling with the balance,” Grosjean said. “We had some issues, as well, with the brakes over the long runs. We need to look at what we can do better with them.
“Generally, it’s just been a very difficult Friday. The car didn’t perform well – very low grip on low fuel and high fuel.”
Team principal Guenther Steiner added: “We had a lot to do and I think we did a lot. We still haven’t got all the results yet, as we need to go through data.
“I would say the issues with the brakes were mainly because they’re new to us. We need to find out how they work. Going through the data, we will decide tomorrow what we’re doing and how we continue.
“All in all, we had pretty fruitful sessions. We did a lot of laps and we learned a lot. Now we need to get the best out of what we learned for tomorrow to go into qualifying.”
Qualifying for the Russian Grand Prix is live on CNBC and the NBC Sports app from 8am ET on Saturday.