STP Heavy Duty Brake Parts Cleaner: Uneven breaking noise and chattering can be caused by break shoe and pad lining dust, brake fluid seepage and slippery road film that contaminates break drums and rotors. Use STP Heavy Duty Brake Parts Cleaner to clean brake fuid, oily road film etc,. The unique formula will help improve brake action for a smoother, surer more dependable performance. STP stands for Scientifically