How to Properly Vent a Gas Tank

eHow may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.

Things You'll Need

  • Jack

  • Jack stands

  • Screwdrivers

  • Ratchet and socket set

  • Hand vacuum gauge

  • Canister filter

  • Replacement lines

It is important that all car owners understand the significance of a correctly vented gas tank. Charcoal canisters have been used since 1970 to reduce the air pollution that is produced by a vehicle's hydrocarbon emissions, according to the Family Car Parts website. The filter traps the fumes and sends them back to the engine through a vacuum hose to be thoroughly burned before being released into the air. Regular maintenance of a charcoal canister ensures that a gas tank is vented properly.

Step 1

Elevate the back end of the car by using a jack and jack stands. The charcoal canister will be located near the fuel tank on the driver's side of the vehicle. Inspect the canister for any cracks, leaks or strong fume smells.

Step 2

Use the hand vacuum gauge to test that the canister is still sealed tightly. If the canister appears to be in good condition, check the air filter to see if it needs to be replaced. The iCar website explains that an air filter should be replaced if it is damaged, dirty or unplugged.

Step 3

Replace the charcoal canister if any damage is located during the inspection. Use a flathead screwdriver to carefully disconnect the plastic electrical and vacuum lines that are connected to the canister. Inspect the lines to ensure they do not need to be replaced.

Step 4

Use the ratchet and socket to loosen and remove all of the bolts that are holding the charcoal canister in place. Take the old canister out from underneath the car. Install the new canister by positioning it correctly and then securely bolting it in place.

Step 5

Reconnect the electric and vacuum lines to the charcoal canister. Test the new canister to ensure that it is working correctly and securely fastened in place. Carefully remove the jack stands and lower the vehicle with the jack.


The charcoal canister and the used filter are classified as hazardous waste material due to the constant exposure to gas tank fumes. As a result, they must be disposed of correctly for environmental safety purposes.


Inhaling fuel vapors is a potential health risk, so the vehicle should be worked on in a well ventilated area. Wearing gloves and a ventilator mask is recommended in order to limit direct personal contact with the fumes. Also, gas fumes are highly flammable so there should be no sparks, fire, or a heat generating source around the vehicle in order to prevent series injuries.