How to Detect a Diesel Fuel Leak

You can test for diesel leaks at home, and do not need to spend the time and money required to bring your vehicle to a local shop. By adding a basic detection dye to your fuel tank, you can perform a quick diagnostic test in order to decide if your vehicle will need further maintenance to repair a leak. You can purchase the detection dye from places like Surf-Prep, a dealer in Kentucky. The price of the dye ranges from $22-$96 and contains enough dye to treat 1,000 gallons of fuel.

Things You'll Need

  • Fuel leak trace dye
  • Ultraviolet light (black light)
  • Pour leak detection dye into the fuel tank of the vehicle that you're testing, adding one ounce of dye for every 10 gallons of diesel fuel.

  • Let the engine run for two to three minutes so that the dye will be distributed throughout the fuel system.

  • Turn off the engine.

  • Check for leaks in every area of the engine using a black light. If there is a leak, the detection dye will glow green or pink under the light (depending on the brand of dye used). If you do detect a leak, bring the vehicle to your local repair shop immediately. This is not something that you can fix yourself.