1994 GMC Suburban Owner's Manual - Page 259

While refueling, hang the cap insidethe fuel door. To take off the cap, turn it slowly to the left. 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. When you put the cap back on, turn it to the right until you hear a clicking noise. I NOTICE: If you need a new be sure to get the right type.Your dealer cap, can get one for you. If you get the wrong type, it may not or fit have proper venting, and your fuel tank and emissions system might be damaged. 6-13