3 ways to clean a fuel tank

It doesn't matter if you plan on restoring an antique car or maintaining a lawn mower or motorcycle, chances are you will need to clean the fuel tank at some point. If you are new to this, this task will likely seem daunting. However, with a little effort and knowledge, you will be able to successfully clean the fuel tank free of contaminants and debris that could damage the engine.

Steps

Method 1 of 3: Clean the Tank of a Motorcycle or Small Engine

Step 1. Disconnect the tank

Before carrying out any operation, you must disconnect the tank from the machine. If you skip this step, you won't be able to safely access or clean the tank. You must untie it and remove the screws or bolts that keep it secure.

For lawn mowers and similar items, you must remove the fuel line and spark plugs.
For motorcycles, you must remove the radiator cock, the fuel cap, and any hoses that may be attached to it.

Step 2. Seal the fuel line

Once you have disconnected the line, you must seal it. If you skip this step, not only can the remaining fuel run out of line, but dirt or other objects could end up inside, causing engine problems.

Take a smooth-faced clamp and connect it to the line near the carburetor.
Separate the line and the carburetor.
Lay the line on a bucket and remove the clamp.
Let the line drain into the bucket.

Step 3. Empty the tank

You must pour the remaining fuel into a container that is resistant to this substance. If you can't get all of it out, you can use a suction hose or similar device to extract the fuel from the tank.

Let the tank dry completely.
If you don't drain the remaining fuel, you won't be able to clean the engine properly. Therefore, you must make sure to extract the entire contents of the tank.

Step 4. Check the tank

You should take the time to properly examine it and spot any issues that may undermine its integrity. Damage, rust, or other problems can pose potential safety hazards or compromise the integrity of the engine.

You should place the tank outdoors and in broad daylight so that you can see inside. If you need more light, you can turn on a flashlight inside the tank.
Pay particular attention to wear, rust stains, or defects in the tank material.
Make sure to check the fuel filter to make sure it's clean. If not, you must replace it.

Step 5. Spray high pressure water over the tank

By performing this procedure, you will break up and remove all accumulations that are at the bottom of the tank. At the same time, you will avoid introducing chemicals (such as detergent) that can cause engine problems.

You should set the hose and sprayer on a high pressure setting.
You may have to insert the hose and point the sprayer in various directions inside the tank.
Consider using a pressure washer or pressurized water machine if you have substantial buildup of rust inside your tank.

Method 2 of 3: Clean a car's tank

Step 1. Use a jack to raise the car

Before removing the tank, you need to raise the car. You should perform this procedure by placing a mechanical jack under the car to suspend it in the air. This procedure will give you enough space to get under the vehicle.

Consider using two jacks to safely raise the vehicle.
You must place the jacks on the points designated for this purpose under the car. You can refer to the user manual to find the exact locations.

Step 2. Remove the fuel tank from the car

Before cleaning the tank, you need to make sure to remove it from the car. By doing this, you will be able to drain, check, and clean it properly. To remove the tank, you must remove the screws and undo the straps that hold it in place.

Make sure you are not directly under the tank when you disconnect it.
You should use another mechanical jack (preferably an alligator type) to lower the fuel tank.

Step 3. Empty the tank

Once you have removed the tank, you should completely drain all the remaining fuel. The scope of this procedure may depend on the age or style of the tank and the amount of fuel. To drain it, you must do the following:

It uses a suction device to transfer the fuel to a storage tank.
If there is some liquid that you still cannot extract, you should turn the tank upside down and allow it to drain into a container. You will likely find sludge or other debris in the remaining fuel.

Step 4. Degrease the tank

If the tank still smells like fuel after you've drained it, you may need to degrease it, as you will achieve much better results from this procedure.

You can use a degreaser (for example, one from Marine Clean).
Try mixing a dish soap with hot water.
Let the degreaser or detergent-water mixture sit in the tank for up to 24 hours.
If the degreaser (or detergent mix) doesn't work after 24 hours, consider degreasing the tank again for a longer period.

Step 5. Pressure wash the tank

After removing the tank, you can use a pressure washer to spray inside. This procedure will help remove dirt, debris, and small rust residue. In addition, it will help flush out the fuel residue.

You can use a pressure washer or garden hose with a spray bottle to clean the inside of the tank.
You may need to point the sprayer at different angles to remove light rust layers and other build-up of debris inside the tank.

Step 6. Use a cleaning solution

If the tank has a lot of rust or other dirt, you may need to use commercial cleaning solutions to eliminate these problems. These solutions work by chemically breaking down the rust. After applying them, you can rinse and remove the residue from the tank.

You can try professional-grade acid solutions to dissolve rust in the tank.
You should only use the cleaning solutions in tanks that have been sitting for a long time.

Step 7. Rinse the tank

After using a cleaning solution or even a degreaser (for example, a light detergent), you should rinse the tank several times to completely remove the suds or detergent residue. If you don't remove all the chemical residue from the tank, you can end up damaging the engine.

Once you have smoothed out the accumulated residue and rust, you should empty the tank and refill it to remove any residue that has not been rinsed.
You should rinse the tank until there are no bubbles or foam in the water. You will likely need to do this procedure 2-3 times.

Method 3 of 3: Take some safety measures

Step 1. Let the tank dry before reinstalling it

Once you've cleaned the inside of the tank, you should let it dry completely. If you skip this step, the water can mix with the new fuel and damage the engine or fuel system.

If possible, you should turn the tank upside down to allow it to drain better.
Let the tank dry overnight.
Make sure the tank is not in a humid location.

Step 2. Dispose of fuel properly

After draining the tank, you must dispose of the fuel. If you don't dispose of it properly, you can contaminate the groundwater in your neighborhood.

You must store fuel in approved containers.
Contact your local waste disposal service to find out where you can dispose of fuel.
You may be able to take the fuel to a toxic waste disposal site near you.

Step 3. Consult with a mechanic if you have any questions

If you have a problem cleaning the tank and you have no idea how to solve it, you can consult a professional mechanic. This specialist has likely had to deal with tank cleaning in the past, so they will be able to advise you appropriately.

If you are unsure whether you can safely lift and remove the tank from a vehicle, you can contact a mechanic to do it for you

Step 4. Use the right safety gear

If you are going to work with fuel or cleaning solvents, you should always use the proper safety equipment. If you skip this, you could permanently injure yourself. You can make use of the following: