Red Bull team principal Christian Horner says Max Verstappen's brake fire during opening practice at the Mexican Grand Prix was the result of an issue with an energy recovery setting.
Verstappen pitted with overheating rear brakes at around the halfway mark of FP1 in Mexico, as his Red Bull mechanics used a fire extinguisher to prevent further trouble. The Dutchman had initially remained in his car in the garage, before eventually climbing out when the problem proved to be session-ending.
"We had an issue, with the rear brakes basically overheating," Horner told Sky Sports after the session. "It was an energy recovery setting that we were trying that just got the rear brakes out of control. It damaged a couple of the electric looms and that's caused a bit of down time just to get that fixed.
"The rear brakes got that little bit too hot just on the in lap and the thermal build-up when they stop the car unfortunately damaged the looms."
Verstappen was limited to just 10 laps and ended the session outside the top ten in 14th.
Horner added: "We're higher than most European ski resorts around here. The air is pretty thin so you don't get as much cooling as you would normally do."
Asked if he was confident the issue will be fixed in time for the second 90-minute practice session -- which starts at 14:00 local time -- Horner replied: "Yeah absolutely, no issues there."