What is it, and do I need it?

Ok guys, I've been having some issues with my 75 CJ5, 304. It seems to be fuel related. So I replaced the filter, fuel pump installed rubber line to the carb and rerouted, and now I have pulled the fuel tank off looking for problems.. BUT, on the driver side of the fuel tank are two small hoses going to a small canister mounted in the upper part of the rear wheel well. Out of that canister is a green line running to the engine compartment and a large canister. The PO has removed all the smog junk, and installed an after market carb, etc etc. My question is do I need this stuff, or can I junk it? Here's a pic of the canister in the engine compartment.

 

This Jeep only has 14000 original miles so it may not be worn out.. But it has set a lot over the years, so who knows. Is it gonne hurt anything if I get rid of it?

 

Thanx for the help, I will eliminate it and especially the hoses at the tank. If you've never pulled a tank off a 75 don't.. It's a royal Pain!

 

sparky is correct
part of the vapor recovery system
I wouldn't throw it away if you decide to remove it

 

Ok, the stuff under the rear wheel well is the liquid check valve and anti-rollover valve for the vapor recovery system. The canister under the hood contains charcoal that captures the vapors until they are burned by the engine.

My opinion about this stuff is ... well ... it's good. It works well, has zero effect on performance, is very low maintenance, and you should keep it. The liquid check valve simply keeps fuel from entering the vapor system. The rollover valve keeps fuel from pouring out if you put the rubber side up. The canister removes the vapors from the vented air - fumes come out, past the check valve, through the top of the canister and clean air exits the bottom of the canister. When the engine is running, a slight vacuum is applied to the top of the canister, reversing the air flow and purging the fumes from the charcoal. The only maintenance is the filter pad that keeps mud out of the bottom of the canister (washable, or cheap from the parts store), and replacing any worn lines. Best ventilation system going for your fuel tank.

 

Thanks Tim
I know you are better at explaining "how it works" than I