Chevrolet 2001 Express Van Owner's Manual page 275

If your vehicle has a diesel engine, see "Filling Your
Tank (Diesel Engine)" in the Diesel Engine Supplement.
6-6
The fuel cap is behind a
hinged door on the driver's
side of your vehicle.
While refueling your
vehicle, hang the cap by the
tether from the hook on the
filler door.
To remove the cap, turn it slowly to the
left (counterclockwise). The cap has a spring in it; if
you let go of the cap too soon, it will spring back
to the right.
CAUTION:
If you get gasoline on yourself and then
something ignites it, you could be badly burned.
Gasoline can spray out on you if you open the
fuel filler cap too quickly. This spray can happen
if your tank is nearly full, and is more likely in
hot weather. Open the fuel filler cap slowly and
wait for any "hiss" noise to stop. Then unscrew
the cap all the way.
Be careful not to spill gasoline. Clean gasoline from
painted surfaces as soon as possible. See "Cleaning the
Outside of Your Vehicle" in the Index.