Not for the first time in pre-season, Red Bull have called an early end to a day's testing due to problems with the RB10.
When Sebastian Vettel managed to cover 59 laps on Day Two in Bahrain, Red Bull had taken that as a sign of encouragement.
The laps continued to flow on Day Three with Daniel Ricciardo in the cockpit of the RB10.
However, after 28 laps the team discovered a mechanical problem with the RB10.
As such Red Bull opted to park the car for the day in the hope of getting it right for Saturday's final day of the second test.
"It was going okay," revealed Ricciardo, "I did some good laps and those came off the back of the more than 50 laps Seb did yesterday, so we're getting there.
"Obviously, I would have liked to do more this afternoon but we still have tomorrow ahead of us and it's important to be ready for that. The car is definitely making progress though.
"It's coming together bit by bit. We'd love a big chunk all at once but obviously that's not the way these things work, so we have to be a bit patient for now. However, it is coming and we're heading in the right direction.
"Tomorrow it would be nice to get more laps in and then roll on next week."
Ricciardo's best time for the day was a 1:40.781.