Hi, I recently noticed a leak at my fuel sending unit and replaced the gasket. I wasn't too confident in the seating of the gasket but I put a couple gallons of gas after replacement and no leak. Yesterday tanked up and it began leaking again. Possibly there wasn't enough gas to reach the top of the gasket before. Any tips on this gasket replacement? Do I have to remove tank to ensure correct placement? Any way to hold the gasket in place while securing the fuel sending unit? How much should I turn the lock ring? I see three tabs that sort of point outwards, where should they be when I'm done turning lock ring? Thanks!