Failed smog test fuel tank not holding vacum

Okay so here is the low down. Removed OLD sender no filter no float really crappy. Installed NEW stainless one with gasket the new hold down ring would not hold sending unit firmly installed old hold down ring works perfect. Installed new stainless ground clamp it also was broken on car. Installed new vent hose and clamp. Installed new fuel line. So started car fuel gauge not working but moved on to filer neck grommet will trouble shout tuesday after smog check retest. Oh sending unit I removed was very cracked not leaking fuel but not air tight.