One problem related to brake whining noise has been reported for the 2004 Toyota 4Runner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota 4Runner based on all problems reported for the 2004 4Runner.
When stepping on brakes, pedal vibrates and gets very soft. Vehicles stopping distance is marginal at best. Rotors have been "cut" already with just 13k on the vehicles due to rust build up. Boch Toyota in norwood mass. Tells me that the brake issue is "normal" !! there is also a loud whining noise when applying the brakes. They tell me this is normal also ! also, the tires had to be rebalanced at 13k as I was told they where "cupping". Sounds like there is a front end issue with the 2004 4-runner.