Abstract: An ink delivery system for delivering ink to an inkjet printhead includes: an ink tank; the inkjet printhead having a printhead inlet port and a printhead outlet port; an ink supply line connected between the ink tank and the printhead inlet port; an ink return line connected between the ink tank and the printhead outlet port; an ink recirculation pump positioned in the ink return line; an ink filter positioned in the ink return line; a bypass line for bypassing ink around the ink filter; a bypass valves for controlling flow of ink either through the ink filter or through the bypass line; and a controller for coordinating the bypass valve and the pump. The controller is configured to pump ink from the printhead outlet port to the ink tank via the bypass line when the return line contains air.