2003 Toyota Sequoia brakes problems

When we first bought the vehicle the trac system lights kept coming on and the brakes felt mushy; we took it in to toyota and they replaced the computer system which seemed to rectify the problem. Then about 9 mo to a year later the lights kept coming on again and the brakes failed twice, toyota stated they would replace the brake system fluid and the master cylinder at our cost because we had taken it elsewhere and they felt that it had contaminated brake fluid, which our mechanic stated in writing was not.

2003 sequoia. Vsc/trac lights come on just driving down the road. Plus parking brake light. Have to shut car off to reset. The dealer said my computer is not part of the recall so I must pay out of pocket. Looked on-line and found dozens of sites and thousands of people with the same problem.