One problem related to brake fluid leak has been reported for the 2004 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota Sienna based on all problems reported for the 2004 Sienna.
I owe a 2004 Toyota Sienna. Within the last 30 days I had to replace my brake master cylinder at my local Toyota dealership (over $1500) due to a brake fluid leak which caused brake fluid to accumulate into the booster and into the engine (and the brake light to illuminate). This is a very similar to the problem which caused Toyota to issue the recall that was announced on October 20th with the Toyota highlander model. I feel the recall should be extended to the Sienna model. I contacted Toyota, and they will not offer any reimbursement or relief for me.