One of these chambers, on the side of the brake master cylinder, contains a constant ... this would fit with your description of the problem getting worse gradually. Unfortunately, I suspect ...

The brake master cylinder is the first component in a vehicle’s braking system, activated by depressing the brake pedal. The pedal pushes a piston through this cylinder, forcing brake fluid ...

Brakes are your vehicle's most important safety system. Under normal conditions, a driver exerts about 70 pounds of force on the brake pedal (about the same amount of effort it takes to bite into ...