Fuel pump/sender question?

[AdrenalineS14]

hey guys i got a 95 s14 and the gas guage is alittle funky so i decided to go in the back and possibly check if the sender unit might be off the bracket inside the tank.... well when i took off the cover to get to the pump assembly i noticed that(facing the trunk) the left side hose has a small tear on it, im not sure but heard those are fuel vaccum lines??? idk I want to replace that hose... but wondering what affect that hose is doing and what damage that tear/leak might be doing, i ask this cause my gas milage has been kinda crappy lately too THANKS for your inputs people of zilvia