One problem related to brake master cylinder has been reported for the 2006 Toyota RAV4. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Toyota RAV4 based on all problems reported for the 2006 RAV4.
At first, when the brake pedal was depressed, a hissing sound appeared to come from inside the vehicle. The vehicle still braked normally, requiring the usual distance to stop. However, after some time, the "brake" light came on, and braking feel completed changed, requiring the pedal to completely be depressed just to slow the vehicle down to a stop. The brake fluid level in the master cylinder was at the proper (maximum) level and no leaks appeared around the brake calipers / pistons and ground. It seemed several owners of this generation of Rav4 (3rd generation) had exhibited similar symptoms pointing to a "brake booster" failure. The vehicle was taken to an independent, reliable shop and the "brake booster" was verified to be the problem.