Need 95 Blazer Help Bad!

[Spl170s]

dropping my tank in my 95 4 door blazer. been having fuel issues where my truck wont start, checking with guage, it just doenst get up to 60psi to start it with.......and seems to bounce around alot to get there...... figured bad pump, so i started taking it out.

 

upon lowering tank, i noticed a rubber hose unhooked around the end of the tank where the pump is at...... there is some sort of black plastic vent/switch/valve or soemthign there that wasn't hooked up...there is another on the other end of the tank.....

 

what is this thing and what does it do for the truck???? what would happen with it unhooked? i need to know what it is even so i can buy another...

 

any help is appreciated!

[Spl170s]

got it figured out. calling it a rollover valve on the forums?

 

regardless it is at dealer in stock..

 

thanks