Replace A Gas Cap Cover

Replacing a gas cap requires untethering the retaining ring or cord.

A fuel cap serves to improve safety, reduce emissions and increase fuel economy. Without a fuel cap, gasoline can evaporate from the tank, which wastes gas and produces environmentally harmful hydrocarbons. The vapors also pose a safety hazard, because of their flammable nature. Fuel caps are easy enough to unscrew, but there may be a retaining ring or cord that prevents complete removal.


1. Purchase a new gas cap cover. Specify the year, make and model of your vehicle. Choose between a locking gas cap or a one that does not lock. If you already have a locking door to your gas compartment, you probably do not need a locking gas cap. Choose whether you want an OEM or aftermarket part. OEM parts are the original equipment from the manufacturer. Aftermarket parts are third-party productions designed to meet the parts’ specifications. Aftermarket products are generally cheaper, but there might be slight differences in design and function.

2. Unscrew the old gas cap in a counterclockwise direction. You may have to place downward pressure to accomplish this. Some gas caps unscrew completely. Others might require a small rotation before pulling straight out.

3. Locate the retaining ring or cord. This will be a plastic tab or wire that connects to a ring around the opening to the gas tank, or it might be attached to the inside wall or door of the gas compartment. The latter will usually be attached via a small clip.


4. Grab the edge with a pair of needle-nose pliers and work the ring off the end of the gas tank opening. If you have a cord attached via a clip, use the needle-nose pliers to pinch the two protruding tabs to open the clip. The actual mechanics will differ from manufacturer to manufacturer, so if you have difficulty, consult a shop manual specific for your vehicle

5. Attach the retaining ring or cord of the new gas cap exactly how the old one was removed.

6. Screw the new cap into place, just how the old one was removed.