When a diesel generator set experiences oil, water, or air leakage, it can lead to increased fuel consumption, 

accelerated wear of components, reduced power output, and other malfunctions. Therefore, timely repair is essential. 

Below are the causes and treatment methods for oil, water, and air leakage in diesel generator sets:

**I. Causes of Leakage**

(1) Friction and wear between moving parts during diesel engine operation gradually alter the geometric shape and dimensions of the components.

(2) Improper use and maintenance, such as loose screws, missing sealing rings, or gaskets.

(3) Incorrect disassembly and installation of components. The use of improper tools or failure to follow disassembly and 

     installation procedures can cause component deformation, damage to contact surfaces, and contamination, leading to poor sealing.

(4) Aging and deterioration of components. For example, rubber oil seals or water seals may deteriorate over time due 

     to prolonged exposure to oil or water corrosion.

**II. Hazards of Leakage**

**(1) Oil Leakage**  

Oil leakage in the diesel engine's lubrication system reduces the oil level in the oil pan. In severe cases, 

components may not receive adequate lubrication, leading to burnout. 

Fuel leakage in the diesel engine's fuel supply system can introduce air into the fuel lines, 

making the engine difficult to start. It also results in energy waste, economic losses, and environmental pollution.

**(2) Water Leakage**  

Water leakage in the diesel engine's cooling system not only complicates refilling but, in severe cases, can cause cylinder head cracks. 

For water-cooled diesel engines, water leakage from the cylinder liner sealing ring dilutes the oil in the oil pan, accelerating component wear. 

In extreme cases, it can lead to bearing seizure.

**(3) Air Leakage**  

Air leakage at the junction between the engine block and cylinder liner can burn the cylinder gasket, 

making the engine difficult to start and reducing power output. Air leakage in the intake system allows dust to enter the cylinders, 

accelerating wear on components such as cylinder liners, pistons, piston rings, valves, and guides. This results in difficulty starting, 

increased fuel consumption, and reduced power.

**III. Treatment Methods**

**(1) Gasket Addition Method**  

For oil leakage at the anti-leak gasket of diesel engine oil pipe joints, add a thin, 

double-sided smooth plastic gasket on both sides of the anti-leak gasket. Tighten firmly to prevent leakage.

**(2) Shellac Solution Method**  

For leaks at joints such as the fuel tank, water tank, or crankcase, soak shellac in alcohol and apply the solution to the 

cleaned joint to seal the leak. However, due to the high cost of shellac, this method is typically used only in emergencies.

**(3) Oil-Based Sealing Method**  

For leaks in paper gaskets at the oil pan, cylinder head, gear cover, or crankcase rear cover, 

apply a layer of butter on both sides of the intact and clean gasket, then tighten the bolts to prevent leakage. 

When replacing with a new paper gasket, soak it in diesel for 10 minutes before installation, wipe it clean, 

apply a layer of butter to the mating surface, and then install it.

**(4) Liquid Sealant Method**  

For interface or destructive leakage caused by defects (such as pits, grooves, or cracks) in solid gaskets on the diesel engine, 

apply liquid sealant to the cleaned mating surface of the solid gasket. Once cured, it forms a uniform, stable, 

and continuous adhesive peelable film gasket, effectively preventing all types of leakage.

**(5) Anaerobic Adhesive Method**  

For leaks at ventilation bolts, screws, double-ended bolts, or screw plugs on the diesel engine, apply anaerobic adhesive to the cleaned bolts, 

threads, or screw holes. It quickly cures to form a film, filling gaps between parts and withstanding significant pressure. 

It also provides strong anti-vibration and anti-loosening fastening functions. 

This method is particularly effective for leak prevention at high-pressure fuel pipe joint threads.

**(6) Dimension-Restoring Adhesive Method**  

For leaks at shafts and sleeves, bearings and bearing housings, valves and valve seats, self-tightening oil seals, felt cups, 

or packing materials, apply dimension-restoring adhesive to the cleaned worn areas of the mating parts. After curing, 

it forms a wear-resistant, heat-resistant, and mechanically strong film layer. Then, perform machining operations such as turning, 

boring, scraping, or filing to restore the part’s geometric shape and mating precision, thereby resolving the leakage issue.

**(7) Bonding Adhesive Method**  

For leaks caused by sand holes or air pockets in components such as the fuel tank, water tank, oil pipes, 

or water pipes on the diesel engine, apply bonding adhesive to the cleaned damaged area to effectively stop the leak.

**Foshan Generator | Foshan Longhong Electromechanical Equipment Co., Ltd.**  

**www.longhongpower.com**