BMW issued a recall on the X5 model

On certain vehicles, a float switch, which is attached to the brake fluid reservoir cap, could fail at high temperatures (>70 degrees Celsius) and not trigger a low fluid level warning lamp as required by CMVSS 135. Due to tolerances within the switch's magnetic parts, in conjunction with thermal expansion of the switch's plastic parts at these temperatures, the switch may malfunction. Correction: Dealers will replace the brake fluid reservoir cap.