Hydraulics involve the use of pressurized liquid to apply force. In hydraulic braking systems for vehicles, brake fluid is the pressurized liquid used to generate the force. A press of the brake pedal directs the flow of brake fluid from the master cylinder to the calipers, where it applies pressure on the piston inside the caliper, which forces the the brake pads against the rotors to slow or stop the vehicle. A brake fluid flush involves replacing the old brake fluid with fresh brake fluid to ensure better braking performance and longer brake system life. Related searches include automotive fluids and transmission fluids.