Install Mimaki manifold correctly. You should follow Mimaki Services manual and especially you should install screws in order as manual steps otherwise installation printhead will fail if you install screws in wrong order. Like you must follow install the first screw firstly and then second screw and then third screw. You can not install the third screw first. Wrong order install screw can not keep the seal between printhead and cap top perfectly and so you will fail to suck out ink.
Ink line maintaining is the most challenging job and it including printhead installation and maintaining.
Keep level is the key for manifold installation.