Three problems related to brake disc pads have been reported for the 2008 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Toyota Sienna based on all problems reported for the 2008 Sienna.
I drive about 5,000 miles a year, in the beginning of 2012 I was told my brakes did not pass the state inspection. At this time I had around 20000 miles on the van. The reason of the reject was rust on the rotors, it was so bad and the rotors were so thin and of a poor metal, they could even be worked on. I had to replace the rotors and pads on all 4 wheels.
During a 30,000 mile check up on our 2008 Toyota Sienna all wheel drive van, we had to replace the front and rear breaks because they were ground down and dangerous, according to our Toyota dealer where the repairs where made. Pads had to be replaced, rotors had to be ground down for both front and rear. All the mileage is long distance highway driving. There was no accident but the dealer seemed very concerned.
2008 Toyota Sienna van. Brakes are soft and have gotten progressively worse with time. At 29000 miles the brake pedal fades completely to the floor. The dealer examined the vehicle and replaced the rear brake pads, the front brake pads are low but still within specifications. The mechanic states that the condition is acceptable. This condition exists at all times, with the vehicle running or not, standing still or moving. Have not tried a panic stop to determine if the vehicle will stop within a reasonable distance.