fuel guage problems

[argonnecycle]

I replaced the fuel tank sending unit on my 1990 festiva ,the old one wuold only read three quarters when full and eventualy died. installed anew sender from a pick n pull and it checked out but it still only reads three quarters, is this a problem whith the guage.anybody have an idea?

[Studebaker]

Its either the sender or the gauge. Remove the sender from the tank and ground it. then move the float up and down. Seeing if the guage reads full. I think if you bypass the sender the guage will read full. Could be an adjustment. Also you can replace the cluster fairly cheap.