Classic/Antique Car Repair: Pontiac Gas Tanks (drain), shop vacuum, gas tanks

Question
Hi
My 1968 Firebird has sat for near 10 years and the time has come, so what is the ideal way to drain the old gas out?

Answer
Some cars came with a drain plug, and some did not.  Take a look to see if there is a threaded plug on the bottom of the tank.  If there is, that would be your drain.

If there is nothing on the bottom of the tank, you'll need to take the fuel line fitting out off the tank and put on a rubber hose with an adapter so that you can get a good seal, then use your "wet and dry" shop vacuum to get the gas flowing into a container that is lower than the bottom of the tank (even when the container is full!), so you'll probably have to put the car up on a lift or at least some sturdy jack stands.

There is an easy way, if you can get the car running by feeding it gas from another source - I use an "IV bottle" approach to supply gas directly to the carburetor from a gas can that I hang on the leading edge of the (open!) hood, and run a line to the carburetor fuel inlet.  Then once you have the engine running on fresh gas, let the fuel pump suction the old gas out of the tank, just put a temporary line to a container alongside the car - make sure it is big enough.  If the fuel pump is healthy, it will pump about a gallon every two minutes or so, and you can clear out a tank pretty quickly.

Good Luck, and be careful!

Dick.