Hi, I have petrol (gas) leak at rear of car right hand side in area of pump & filter regulator - investigation shows its coming from the charcoal canister so potential candidates are purge solenoid valve which could draw fuel through if stuck open but unlikely because it does it without engine running or more likely a failing filter regulator where diaphram has corroded wondering how to prove maybe take connection from filter to canister off and see if gas leaks wirh ign on or some other way, ideas please and if canister is full of gas is it a good ided to try to empty to stop raw fuel being drawn into engine?