Brand New; The red liquid is protection liquid but not ink. It can keep the printhead out of dry. If without these liquid after long-term storage will affect printing quality.
This printhead has not changed the printhead adapter.
After changed a new printhead there is air so please wait sometime to let the ink flow in then clean 2 to 3 times will be done. If still can not work please check whether there is air in the ink tube or ink cartridge.
Except printhead, ink pump also is the part that will influence the print quality. After you have changed a new printhead still have not improved the print quality while you may also need to change a ink pump.