Pulsating brake

Hello, if the brake pedal pulsation is rhythmic with rotation of the wheels as you are slowing down, it is likely due to the front brake rotors (and sometimes rear rotors or drums) being out of round due to several possible causes. One cause is fluid that is overheating due to being over 3 years old and full of moisture. One cause is the rotors being too thin and overheating as a result. In any case, you'll need to have the brakes checked, the components measured and rotors resurfaced if that is possible to be done safely. The brake fluid should be changed at least every 3 years to prevent the likelihood of moisture contamination causing a lower than usual boiling point resulting in brake overheating.