Gas gauge slow to respond on fillup

[97exploder19]

Ive got a 99 5.0 with a new fuel pump/sender unit. I had my normal Ford Independent shop do the work since its gotten cold here in Michigan. However, Ive noticed that my fuel gauge is very slow to respond to a fill-up, even with the truck off. Sometimes I have to wait about 15 minutes or longer for it to show a full tank. The sort of thing that would happen when you leave the trunk running while filling up.

Any ideas on what the issue could be? The new fuel pump/sender is working great besides this issue.

 

[koda2000]

The sender for the gas gauge is part of the fuel pump assembly. You don't say what brand you purchased, but the sender may not be good quality. Other than replacing the unit a second time, I don't think you can do much about the slow response.