Two problems related to brake disc caliper have been reported for the 2004 Toyota Prius. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota Prius based on all problems reported for the 2004 Prius.
When stopping suddenly sometimes the brakes on my 2004 Prius would not respond immediately as they should. They would release the calipers completely and the only way to stop would be to let off the brakes and press them again. It does not happen often but it is regular enough that this has always concerned me very much. Today I was following a car who slammed on their brakes very suddenly and therefor I also had to slam on my brakes. This same issue occurred and I did not have time to release the brakes and press them again causing me to hit the back of the car that I was following. I maintain my cars very well and this car was in top condition with brand new tires. The brakes do not even activate enough to squeal or leave any rubber behind. There is no way that I could possibly have stopped in time. This is not safe and needs to be resolved for other people who have these cars.
Fluid on left rear tire rim and loss of hub cap. Discovered leaking brake cylinder assembly and soaked disk brake pads. Master cylinder brake level down to to minimum fill level. Brake fluid pooling on garage floor under left rear wheel.