If you just purchased a new gas tank for your motorcycle, customized your existing gas tank, or added a fuel sight gauge it is imperative that you pressure test your gas tank to be sure there are no leaks before you line, prep, and paint the gas tank. Whenever we weld on a gas tank we pressure test that tank to avoid any costly reworks after the tank is painted.
- Plug all openings in gas tank
- Pressurize gas tank to 5-10 psi
- Submerge gas tank in water
- Note any bubbles and mark tank if any leak
- Repair tank and retest
- Clear any water from raw tank
2. Fill the tank with air. We use a hand pump to reach the necessary 5-10 psi. I suggest that you do not use compressed air to fill the tank as it is difficult to control the volume of air going into the tank. Do not exceed 10 psi as deformation can occur or seams may split. I have seen this happen and you will have a lot of work to do to fix the issues.
3. Close the petcock to keep pressure in the tank. Submerge the tank completely in a tub of water. We use a Rubbermaid container, but I have heard of people using bathtubs, laundry basins, kids' pools, etc.
4. Any bubbles that are consistently coming out of the tank indicate a leak. Look very closely at any potential leaks and mark them with a paint marker or permanent marker. Sometimes these bubbles can be difficult to see where they are originating from, so be sure that you are finding the original source of any leak.
5. Dry your tank off with some compressed air and repair any leak in the tank. You will need to weld or solder the leaks as necessary. Do not rely on your tank liner to repair pinholes and leaks. Be sure to pressure test again after any repairs.
6. When your tank is consistently holding pressure and you have no bubbles, you can rest assured that your tank is ready to be lined with a good tank liner.
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