The ToolPRO Brake and Clutch Bleeder allows you to change the hydraulic fluid in your vehicle by yourself. The unit's use of gravity pressure allows you to manage this operation alone, eliminating the need for someone to pump the brake pedal. Simply fill the reservoir bottle with a small amount of fluid , enough cover the bottom of the tube to act as a fluid valve and position it above the bleed nipple height using the magnet to help move any bubbles up the hose and away. Loosen the bleed nipple and pump the brake pedal slowly to purge air from the system. Extremely versatile, this bleeder is capable of working on all hydraulic systems and works on both wheel and master cylinders.