Inked Dory grips are designed with a very tight tolerance for a "hydraulic seal." If that seal is compromised, capillary action and machine vibration do the rest—sucking ink up like a straw.
Regularly lubricate the needle and main components using brand-specific lubricants to maintain a smooth seal. 2. Air Leaks (Bubbling in the Cup) inkeddory inked dory leaks fix