hey guys im new here but i have a problem,i noticed my gas tank has a crazy amount of pressure when i unscrew the cap,i looked at the top of the tank and it has two spouts on top of the tank,one goes to the fuel filter it runs down the right frame rail,and the othe line goes to the rear of the fuel plinume bye the firewall,i thought it was the return,but there was one hose from the charcoal can just laying open under the truck but there is no where to hook it up i was going to put a tee fitting in the hose that runs beside the filler neck and plug it in there ,i thought that might help releive some pressure the tank has a tiny leak in the bottom and i thought it might be from the pressure,if this sounds like it could be the problem i would appreciate someone telling me and also what all tanks will interchange with my 88 toyota 4x4,thank you very much for any help.

 

A pressure release is normal

 

The fuel system is supposed to be pressurized. If you take the fuel cap off and it doesn't go "pshhhhh" you have a problem.

The charcoal canister is also supposed to have a hose coming from the bottom, leading to "nowhere" this is a vapor drain.

The tank is NOT supposed to have a leak however. That is likely caused by rust, or a seam leaking in the tank.