What Were They Thinking -71ca Gas Tank

I just removed the gas tank on my 71 Renegade II from California. I had a leak around the ring securing the sender unit and am going to replace all the original rubber hoses. This is the all original Jeep I brought back from northern California 2years ago. It still has all the "great emissions".
What possible reason is there a small breather tube coming out of each corner on the top of the tank with a hose or hose/tube/hose going to the charcoal canister located in the back of the rear dr side wheel well. Why why why would they need 4. There is a 5th line coming off the canister that is routed up towards the engine along with 2 lines from sending unit.
I know the 2 lines from sending unit are suction and return from fuel pump. I'll have to trace the one from the canister.
Do all California gas tanks from the early 70's have that many vents or was it just Jeep?
I'd like to just cap off 3 of the vent ports on the tank and the canister but kinda want to keep it original.
https://beamingpix.com/image/eZrkn
https://beamingpix.com/image/eZ976

 

If you have a copy of the service manual, on page 112 explains why there are 4. There are 4 lines so that if you are on a hill or side slope at least one of the 4 vents will be open with no liquid in it so it can vent at all times. That I know of only ones sold in California had that system. Mine bought here in Wyo. did not have that system.

Mike

 

That line probably goes to the inlet of the air filter.

 

Thanks for the info. The leak on top ended up being the fuel return line which pretty much disintegrated when I twisted to remove it. The tank inside and out is amazingly rust free. It did have a small crack in the bottom of the tank that I am getting repaired.

It sure is nice not having to fight rust. The hose clamp even unscrewed easily!

 

Just out of curiosity...do charcoal canister wear out over time,plug up and quit venting or??