Fuel contamination remains a persistent issue for construction machinery operators. Beyond various filtration measures, fuel tanks themselves require periodic cleaning to alleviate the burden on filtration systems. Here, we share methods for cleaning fuel tanks. Additionally, as cleaning is concerned, the engine cooling system also necessitates periodic cleaning, which we shall cover here as well.

The simplest method is air-blowing cleaning, requiring only a small air compressor. During cleaning, drain the fuel but take care not to empty the tank completely; retain a portion of fuel. Then, feed compressed air through a plastic tube into the bottom of the tank. This causes the diesel to churn vigorously, achieving a thorough clean. During this process, continuously adjust the position and direction of the air tube to ensure the entire tank is cleaned. Immediately after blowing, drain the tank completely to allow suspended impurities to flow out with the diesel. If the drained diesel appears dirty, repeat the cleaning process until the discharged fuel is free of impurities.

The steam method yields good results but is only suitable where conditions permit. If steam is available, it is worth trying. During cleaning, drain all diesel, remove the tank, then fill it more than halfway with water. Introduce steam through the filler neck into the water, causing the water inside the tank to boil. This process takes approximately one hour. By this stage, gummy deposits and various impurities adhering to the tank walls will have dissolved into the water or peeled away from the surfaces. Two consecutive cycles will thoroughly cleanse the tank.

Another common method employs solvents, specifically sodium hydroxide (commonly known as caustic soda or lye). First, clean the tank with hot water, then dry it with compressed air. Next, fill the tank with a 10% sodium hydroxide solution for soaking, and finally rinse the interior with clean water.

Cleaning the engine cooling system also requires sodium hydroxide preparation. After the engine has been switched off and cooled down, drain the coolant. Fill the system with a 15% sodium hydroxide solution. After 8 to 12 hours, start the engine. Once the temperature rises to 80–90 degrees, switch off the engine immediately and drain the cleaning solution to prevent scale precipitation. Then flush with clean water until thoroughly rinsed.

For aluminium alloy cylinder heads, prepare a cleaning solution using 50 grams of sodium silicate (commonly known as water glass), 20 grams of liquid soap, and 10 kilograms of water. Introduce this mixture into the cooling system, allow the engine to run for approximately one hour, then drain the solution and rinse thoroughly with clean water.