I have a persistent leak on the drivers side lower tank connector plate at the lower rear corner of the tank jus ahead of the rear tire. I tightened the 8 bolts in the summer and the leak stopped but now it has returned even though the car a 98 ragtop has just been sitting since Nov 1.

Any suggestions how to drain the tank so I can pull the plate off and seal it better? suggestions for what sealer to use?

Here is a link that has a video on draining the tank. Basically it will work on the C5 also even though they show a C6. If you need help on the jumpering let me know.

https://www.corvetteforum.com/forums...tank-leak.html

Thanks for the link, seems to be working although C5 FP relay is 35...takes a long time to drain as it seems the fuel from 1 tank or the other has to make it over before I can empty both tanks.

Glad it is working. Yes, the right tank has to empty first and then the left. Here is how the systems works:

http://www.hessh.de/Corvette/FuelTankSystem.pdf

Well everything was OK gauge said 1/2 a tank when I started to drain it but I only got about 4 gallons out and now the pump just pumps air and a bit of fuel, the gauge still reads 1/4 tank so I suspect the right side is still 1/2 full but this is a 98 so I guess the fuel system is different.

I can hear the pump sucking air in the left side tank.

If I can't get all the fuel out I guess I can still pull the left side lower plate that is leaking off to seal it with permatex sealer.

The jet pump (no motor) in the right tank may not be transferring fuel over. The right side is supposed to drain first by design.

Not at home now to see if there is a way to isolate the right tank feed. It should not feed without fuel flow caused by the left pump. Just not sure if the right tank might siphon on you somehow.

PLEASE be careful and don't let fuel dump on you. Have a friend help you with a big fire extinguisher. Disconnect the battery before you start work. Safety first.

There is no sealer/glue needed, or required, when installing the gasket. If it is damaged or compromised, replace it. Check the mating surfaces on the tank and hat as well. The new gasket comes with 7 breakaway bolts (one extra). The instruction sheet that comes with it explains more.
Hopefully no one has been in there before you and screwed the tank threads up. If so, fix it/them properly.

The AC Delco part number for your car is G4. It's not the cheapest gasket in the world, but if you need one, get it. Don't cheap out and try gluing.

Ordered the gasket set from Rock Auto and it's on its way, $90.00 cdn for a gasket with shipping.
Seems like a lot of plumbing and wiring to remove so hopefully the instructions cover how to get them off.

Right side tank is still 1/2 full ( 1/4 tank), I assume because the return valve is on the fuel rail so no fuel is returned and the jet pump does not work to take fuel from the right tank.

For the record, you will be receiving one (1) gasket and seven (7) small bolts. After removing the three fuel lines and the one electrical connector plug (and of course the six bolts), the entire fuel pump/sender assembly must be removed from the tank in order to fit the new gasket. Do some searching for this, as several people have posted "how tos" so-to-speak. After getting the fuel pump/sender part way out, you MUST unclip the wire float arm so it's loose, in order to gently twist/turn the float arm and pump assembly all the way out together. This is mainly because the float arm is so crooked. A little twisting and turning while you pull everything together out is all it takes, so be patient.
When installing the new gasket, do NOT be tempted to try and "stretch" the new gasket around the hat with the pump/float arm assembly part-way out of the tank. It won't work. As stated, remove the pump/float/sender assembly first.

Here's one link that may help. There may be others.

http://api.viglink.com/api/click?for...structions.pdf

Note: the actual fuel hoses themselves in this "how to" may differ slightly in appearance from yours. That's because the fuel hoses (pipes) on the '97 and '98 C5s are slightly different than the '99 thru '03 model years. For example, you may see some insulating foam and tie wraps on yours, this is normal for the early cars. All the later cars require no tools to disconnect the fuel lines, but you MAY, so I would get both a 5/16" and a 3/8" fuel line tool and have them nearby just in case. They are cheap and any AP store will stock them.

Good luck