Only drive one of your vehicles a few times a year? You’ll store your car for long periods of time, anywhere from a few months to a few years. If you’re one of those drivers who retires your classic car for the winter, you’ll store your vehicle for the season.
No matter the case, before you fire up your vehicle after storage, wait! Make sure you know how to clean a gas tank first.
Immediately after storage is a good time to ensure everything is clean and working properly before you head out on the road—especially when it comes to the fuel tank.
You never notice in daily-use vehicles, but fuel lasts about six months. If a car is stored with fuel in the tank for several months, that fuel can congeal in the tank and cause performance problems.
This guide will walk you through how to clean a gas tank that has been sitting after a vehicle has been in storage for some time.
How to Clean a Gas Tank After Vehicle Storage: Ten Steps
- Drain the gas.
- Uninstall the tank.
- Clean the exterior.
- Wash with hot water and detergent.
- Wipe down.
- Inspect for damage.
- Install a new fuel filter.
- Add antifreeze.
- Set out to dry.
- Reinstall the fuel tank.
1. Drain the Fuel Tank
The first step of how to clean a gas tank is to drain any excess fuel from the fuel tank. In some vehicles, there’s a valve or chock available to make this easy. In others, you will need to siphon out the remaining fuel using a hose and pump.
Drain the fuel into a plastic gas can or a pan. It will likely have rust and sediment, especially near the bottom, so do not plan on reusing this fuel. You’ll need to store the fuel in a fuel caddy until it can be properly disposed of.
(We’ll talk about how to dispose of the fuel and the rinse-out liquid safely later on.)
2. Remove the Fuel Tank From the Vehicle
The next step is to remove the gas tank so that you can clean it more effectively.
First, pull up the manual for your vehicle; they are often available online or by request. Flip to the fuel tank section and follow the instructions to carefully remove the fuel tank from the housing. Initially, you’ll want to leave the fuel pump, valves, and caps in place.
You will want to use a tray to keep track of any screws and fasteners that are taken out during this process. Keep the correct tools handy so you can easily reinstall the tank when the cleaning process is done.
Once the fuel tank is free, you can remove the fuel pump and any valve hardware that may still be attached. Again, follow the directions in your vehicle’s maintenance manual.
3. Clean the Fuel Tank Exterior
The next step of cleaning a gas tank is to cleanse any rust and debris from the tank exterior.
Check for signs of damage or rust from the valves to the bottom of the tank. Scrub away any small spots of rust and wipe away debris or dust. Then, inspect it for holes. If you find any small holes anywhere in the fuel tank, patch them before continuing. This step is small but important.
4. Wash the Fuel Tank With Hot Water and Fuel System Detergent
Now, you are ready to wash your fuel tank. Knowing how to clean the inside of a gas tank is the most important part of this process.
You’ll need a hose (that runs clean, hot tap water) and a safe fuel-system detergent. If you don’t have a hose that runs hot (most people don’t), you can attach a rubber hose to a sink faucet and run the water hot.
Once you’ve hot water into your fuel tank, aim at the sides while filling the bottom. Add a little detergent and coat the inside of the tank, but don’t yet fill it. Swirl your fuel tank to dislodge the last of the fuel and sediment that’s collected at the bottom.
The hot water and detergent will help to break up the thicker buildup. Dump out the tank into a pan, and be sure to collect all the liquid, as it is toxic and should NOT run down your driveway.
Continue this process (using a brush if the fuel tank design makes it possible) to dislodge all rust and sediment inside the fuel tank. To do so, squish hot water and detergent forcefully in the fuel tank.
Repeat the process until the gas tank appears clean when empty and illuminated.
When the fuel tank appears to be fully clean, rinse it with hot water twice more, focusing on coating the sides so that all the detergent is rinsed out.
5. Wipe Down the Fuel Tank
Use a lint-free cloth to wipe down the outside and apertures of the fuel tank. Shake out the tank and remove any moisture from areas you can reach with the cloth. Note: We will use antifreeze to help remove the rest of the moisture in a later step.
6. Inspect for Damage
Now that it is fully clean, here is another chance to inspect your fuel tank for damage. Use a sharp eye to look for any rust spots, small holes, dents, or other signs that your fuel tank may have been damaged in storage or some time before. A flashlight may be helpful to examine the interior surface of the tank.
7. Install a New Fuel Filter
As you reinstall your fuel pump and other peripheral parts, now is a good opportunity to change your fuel filter.
Many people never change their fuel filter, but it’s a vital step in thoroughly cleaning a gas tank. You can ensure that your vehicle provides more optimal performance with a fresh fuel filter in the line.
It helps to have a new fuel filter on hand that is compatible with your vehicle. If not, you can quickly pick one up at the local hardware or auto parts store.
8. Add Fuel Line Antifreeze
To help your fuel tank dry faster, you can add some fuel line antifreeze or water remover. This will help to absorb any residual moisture so that your tank is ready to hold fuel again (much sooner than would be possible without antifreeze).
9. Set to Dry for 30 Minutes
You can now set your fuel tank to dry for at least 30 minutes.
If you don’t have antifreeze or water remover, you may need to wait as much as 24 hours for all water droplets to evaporate from the tank before it is safe to reinstall and fuel up again.
10. Reinstall the Fuel Tank
Finally, you are ready to reinstall your fuel tank. Pull up the manual and check the instructions. Carefully follow the tank reinstallation process, including how to reconnect the fuel pump and valves properly into your vehicle’s fuel system.
Make sure that all the screws and fasteners you collected when removing the fuel tank go back in and double-check your work. You’ll want this process to be perfect before you start driving again.
Refuel the Tank
The last step as you’re finishing up how to clean a gas tank is, naturally, to refuel. If you are sure the tank is installed properly, use a gas can of fresh fuel to refill the tank about halfway so that you can take your car on a test drive. Only fill halfway in case further maintenance is needed.
How to Properly Dispose of Old Fuel
If you executed this process correctly, you’ll have collected leftover fuel and the fuel-detergent mixture poured out of the gas tank. This fuel is dirty and contaminated, meaning you can’t easily dispose of it at home.
The easiest way to dispose of fuel you removed from an old gas tank is to store it carefully in a fuel caddy, then take it to a nearby mechanic or auto body shop. These auto shops regularly dispose of hazardous vehicle fluids, including old fuel from gas tanks, and will take care of it for you.
Safely Storing Your Vehicles With Neighbor
If you’re planning to leave a car unused for an extended period of time, it’s best to focus on how to clean a fuel tank before storage so that no gas congeals in the tank. However, cleaning after storage is necessary if your vehicle is stored with gas in the tank.
Cleaning your vehicle’s gas tank is more than just a preventative measure; it can also boost your car’s overall performance.
To fully optimize your vehicle’s performance, proper vehicle storage for your seasonal or recreational vehicles is essential. You need a parking spot that provides the right location and level of protection. The storage location can keep your vehicle safe and be a launching point for the occasional adventure. You can find that perfect vehicle storage location with Neighbor, a network of peer-to-peer parking spot rentals ranging from shared driveways to commercial warehouse space.
Whether you are storing an RV, four-wheelers, or classic collector cars for short- or long-term storage, you can find the right location and conditions through the Neighbor parking network. Find Neighbor’s Car Storage Near Me to get started.
