When applying the brakes the car doesn't stop smoothly and the brakes seem to vibrate. The vibrations can be felt in the brake pedal.
When braking the car veers off to one side, this happens even on a straight section of road. The car seems to pull to the one side.
The surface of one or more of the brake discs appears to be very rough to the touch. There are cracks appearing in the disc.
On inspection one or more of the brake discs on the car have turned a blue colour that doesn't look anything like the rest.
When you apply pressure to the brake pedal there is a clicking or tapping sound. The sound can be loud or quiet and usually won't be felt through the pedal itself. It will usually sound like it's coming from one of the corners of the car. The clicking will usually increase or decrease in frequency with the speed of the car, ie it will click aster at higher speeds.
When pressing the brake pedal the brakes don't apply in a smooth way, they seem to come on all of a sudden and are more bumpy than they used to be.