88I-ROC

So after a yesr of gas coming out of the gas tank filler opening when tank is full, I finally decided to get to the buttom of it. After doing a little bit of research I found that it would be a good idea to test the EVAP system. I didn't really found any specifics for what I was looking for, so I decided to open a new thread.

Fisrt thing first, what is the best way to test the white check/vent valve that is under the fuel tank and above the axle?
I got a vacuume pump to test the purge valve that is between the canister and the TB and the one between the tank and the canister, but I wasn't sure if I was doing it correctly. What I did was disconnecting them completely and then hook the vacuume pump to the upper inlet of the valve on both of them and start pumping, it seems that the preassure was bulding without any release so I wasn't sure if its good or not...?

Now for the solenoid, I have the later model canister which have the solenoid part of the canister itself and I'm not sure what is the best way to test it in that style, and if I do need to replace it, can I get it by itself or do I need to buy the whole canister..?

Any ideas??

Thanks in advance guys.