One problem related to brake master cylinder has been reported for the 2011 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2011 Toyota Sienna based on all problems reported for the 2011 Sienna.
Had to push brake pedal to the floor in order to stop 2011 Toyota Sienna xle. Gateway Toyota replaced the master cylinder on Friday November 19th. Driving vehicle on Monday November 22nd pedal went to the floor again, difficult to stop. Toyota scheduled to replace master cylinder again on November 23rd. Vehicle only has 5,300 miles on it.