One problem related to power assist brake hoses, lines/piping, and fittings has been reported for the 2001 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2001 Toyota Sienna based on all problems reported for the 2001 Sienna.
Car had been driven for 15 minutes, brakes worked, was parked for 30 minutes and upon pulling out of driveway realized brakes did not function. Was able to brake the car with parking brake. No accident ensued, called tow truck and brought it to service center. Was told that vacuum hose came unattached, so power assisted brakes were not working.