How To Fix A Gas Leak In A Car?

A leaking fuel hole on the ground is an indication sign of a gas leak. Although it may seem alarming, most tanks can be repaired with minimal effort. Before you can make repairs, access the tank, find the source of the leak, and then clean the area around it. Follow the following steps to know how to fix a gas leak in a car.

For a simple but efficient fix, cover the leak with epoxy putty. If you’re looking for something stronger and more permanent, you could weld the leak shut. Welding requires you to drain the tank and clear it completely of fumes. No matter what repair you use, your tank will be back in working order once it has a new, airtight seal on it.

What You Will Need To Repair?

  • Gas tank repair epoxy putty compound
  • Carjack
  • Jack Stands
  • Sandpaper
  • Rubbing Alcohol or other degreasers
  • Clean towel or rag
  • Vinyl or kitchen gloves
  • Safety Glasses
  • Filtration mask

How To Fix A Gas Leak In A Car?

You can know how to fix a gas leak in a car when you follow the below steps by steps process.

1. Jack Up The Vehicle

Jack up the car to a height where you can place the jack stands underneath the vehicle. Once the jack stands are underneath the vehicle, lower the jack to a height so that the vehicle rests safely on the jack stands. And work underneath the car.

2. Find The Leak

Crawl under the vehicle and inspect the gas tank. Find the area where the tank is leaking. There should be an obvious small hole where the gasoline drips or leaks out.

3. Sand The Leaky Area Of The Tank

Use the sandpaper to sand the area where the tank is leaking. Sand an area approximately 1 1/2 inches to 2 inches in diameter surrounding the hole or leak in the gas tank.

4. Clean The Surface

Use the towel and alcohol to clean thoroughly the area that has been sanded. Make sure to remove any dirt, grease, or grime that will prohibit the epoxy from being applied correctly.

Follow the manufacturer’s instructions for mixing the epoxy compound. You may have to mix the compound from two different tubes together for a couple of minutes. Make sure to use it before it dries. Follow the instructions on the packet exactly for mixing the compound.

6. Shape and Apply the Epoxy

Next, cut off a piece of the compound that is about 1 to 1 1/2 inches long. Then, make the epoxy compound’s shape into a small cone shape with a tip at the top and a broader base at the bottom.

7. Insert the Epoxy in the Hole

Once you have correctly shaped the epoxy compound into the shape of a cone, you will need to insert the tip of the cone-shaped epoxy into the hole in the gas tank.

Insert the epoxy compound as far as it will go into the hole and smooth the remaining compound into the area that has been sanded. You can use a couple of drops of water to make the smoothing process easier. and help it blend better into the sanded material.

8. Fill the Tank with Gas

After the epoxy compound has dried and cured, you can fill your car’s gas tank as you normally do. Once you fill the tank, make sure to check the tank again for leaks.

However, in case you have followed the directions above, the leak should now be sealed and the epoxy should hold for many years to come.

Fix A Gas leak By Welding In A Car:

A large leakage can only fix by welding instead of epoxy fixing. So follow the below steps to know how to fix a gas leak in a car.

1. Get A Plastic Or Metal Welder

Most gas tanks are made from lightweight plastic, then to fix it get a plastic welder. In case you’re working on a metal tank, get a stick welder. Both tools work by melting a welding rod onto the leak.

2. Select A-Rod To Melt Over The Leak

The rod should match the tank you’re repairing. Plastic tanks are made out of polyethylene, so choose a high-density polyethylene rod to melt over it. Metal tanks are either steel or aluminum. Using the correct welding stick material makes the repair stronger and more permanent.

Aluminum tanks are much lighter than steel ones. If the tank seems unusually heavy, then you will most likely need a steel rod to fix it.

3. Put On A Protective Mask

Welding produces plenty of heat and fumes, which can be dangerous if you aren’t well-prepared. The mask should be shaded to protect your eyes. Also, wear a respirator for additional protection. Cover up with a long-sleeved shirt and long pants as well. Ventilating your area is also important.

Keep other people and pets out of the room until you’re done with the repair.

Have a base to place a hot welding gun until it has a chance to cool off.

4. Hold The Stick And Welder Above The Leak

Set the gas tank in a stable but accessible spot. Then, plug in your welder, holding it in your dominant hand while it begins to heat up. Position it at an angle with the tip. Then, hold the welding stick at an opposite 45-degree angle with its tip below the welder.

If you’re using a metal stick welder, the stick fits inside the welder so you don’t have to hold it separately. For high-density polyethylene tanks, wait until the welder reaches 325 °F. And for metal, heat the welder to at least 375 °F.

5. Melt The Welding Stick

Start at the top and gradually work your way to the bottom. Wait for the rod to begin to drip into the leaking spot. Once you notice it melting, move the welder and rod at a slow but steady rate around the leak. The melting rod should continue melting onto the leak, covering it with a consistent amount of material.

Coat the entire rim of the leak with filler from the rod.

6. Spread Filler Over The Middle Of The Leak

Move back down the center part of the leak to melt more of the rod and cover up any remaining gaps. Continue working until the leak has been filled with a consistent coating of fresh material.

Note any gaps that haven’t been filled in. Go back and melt more of the rod so they are level with the rest of the tank.

You may notice some uneven spots where you applied too much material by mistake, but these spots can be sanded flat later.

7. Wait About 8 Hours To Solidify

Keep the gas tank in an area with plenty of air circulation. The filler from the melted rod will cool down and harden over time. Once it has had a chance to harden, check it to see if it’s cool to the touch. Place your hand near the repair to detect any heat coming off of it.

8. Use 120-Grit Sandpaper To Smooth Out The Patch

Rub the repaired area with a firm, consistent amount of pressure. Work your way from top to bottom along the weld. Continue wearing it down until it is level and blends in well with the surrounding area. Once you’re done, you can paint the tank if you wish and then fill it with gas.

How Much Does It Cost To Replace The Gas Tank?

Most cars have a metal line that runs the length of the car with rubber fuel lines connecting at either end, one at the fuel tank and the other to the engine. Fixing a leaking fuel line is a simple task for a repair facility and costs between $60 and $120. It can easily be done at home by the above process which costs near about zero.

In case you go to the mechanics for repair the total cost also includes the labor cost. This makes a huge difference between repair shops to shops.


A fuel leak is when gasoline leaks from the gas tank of the vehicle. Underneath the car will be a spot of fuel on the pavement, along with the strong smell of gasoline. A fuel leak should not be ignored, so as soon as you notice these signs, it is time to make an appointment with a mechanic right away.

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