Haley Writes: I have a 2005 Tundra truck with a funny brake problem. When I sit at a light, the brake pedal sinks to the floor sometimes. My husband drove it and it didn’t do it for him. For me, it was acting up about once a week, now it happens more often. Could it be my imagination?
Haley, what you have is a brake master cylinder that is bypassing. The internal hydraulics are failing and it should be replaced with a new one as soon as possible. It will only get worse and then completely fail. When you are replacing the master cylinder is also a good time to have your brake system flushed.