The Haas F1 Team is still trying to get on top of the brake issues which hassled the US outfit last season.
Haas enjoyed a good first week of running in Barcelona, but among the few troubles the team had to deal with was the lack of consistent efficiency of the VF-17's Brembo disc and pad combo.
"We are not completely done with the brakes," said team boss Guenther Steiner after Thursday's running.
"Our biggest problem is the inconsistency. So again, we have sometimes a brake that the drivers are really happy with, and then we get a set which we are not happy with. And we lose a lot of time.
"It is not only the time to change it, because the driver loses the confidence. Then, when you put the next one on, he needs to get into a state again that he is confident about what he gets.
"So we are not done with that yet. We had good brakes on Tuesday and good brakes on today but yesterday that was one of our problems."
In an attempt to solve the chronic brake weakness, Haas trialed products from Carbone Industrie last year.
"We haven’t tested them [CI] enough to know if they are consistent or not. We did a test last year but we haven’t come to a conclusion.
"We need to test them for this year, because we were late with the sign off and we have to produce new brakes because the discs are thicker and we haven’t got them yet.
"We will test them. We just don’t know exactly when or which race we will have them on."
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