all I do when I have to take apart my cluster for things is just put it at the proper level by pushing the needle up past the full mark. Or I Waite till the light comes on and adjust it at that point because you know the proper level at that point. If it fills up but then stops at a half tank then you may have to replace the file gage like I did. The fuel gage in fact all the gages can be replaced individually. Just push the needle down till it stops (just lift it past the black tab)then push a little further it it’s to far then push it up. That’s how I have done mine and it has worked for like 6 months. Plus there is a test mode aswell that I use to adjust the needles aswell.