One problem related to brake foundation components 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.
Vibration in rear brakes causing a harmonic noise when coming to a complete stop or if on a downward incline with brakes applied and just barely inching along. This is not the normal squeal from brake pads. I have been concerned that this vibration is causing other parts to become loose. I purchased the 2001 Toyota Sienna xle van new in sept 2000. All of my service is done according to Toyota's schedule and at Toyota of greensburg, PA. The noise started aprox. Feb of 2002 with 19,000 miles on the vehicle. It was reported to Toyota of greensburg, PA on may 10th of 2002 with 22,166 miles. Between may and August of 2002 the van was taken to the dealer 4 times for this problem. During that time they replaced the linings and drums, cleaned the brakes or did something other but the noise always comes back. On August 5th 2002 Toyota of greensburg told me that Toyota was aware of the problem and working on a fix because it is happening on all Sienna vans since 1998. Between then and April of 2003 I keep asking about the repair and the answer was it is not ready. At that point I went to Toyota's arbitration process but they would not do anything since the van now had over 36,000 miles even though the problem started well within the warranty period. I feel there is a vibration problem (sometimes you can actually see the road wheel vibrating also) that could cause other more serious problems but do not know what else to do. As far as I know Toyota has still not developed the repair.