Yes, you must bleed the brake system any time after you open a brake line. IPD and other parts suppliers sell a brake bleeder (Motive Products Power Bleeder)that enables you to bleed your brakes by yourself. It has a cap that fits onto the master cylinder. Once the bleeder is pressurized, the pressurized air and fresh brake fluid forces the old brake fluid and air bubbles through the brake bleed fittings when you open them. No need to touch the brake pedal. It works pretty well.