Engine compartment inspection for fluid leakage

Engine compartment inspection for fluid leakage is performed during each periodic inspection or servicing. When a client complains that he has noticed fluid on the engine or under the vehicle and finds a lower fluid level, an emergency inspection is performed for fluid leakage.

The color of the liquid is the best indicator of which system is leaking. Engine and transmission oils are black, coolants are orange or green, and power steering oil is red. The smell of liquids can also indicate the type of liquid. Fuel and coolant have different odors.

Identification of fluid leaks on the vehicle

When you follow the trace of a leak, you should know that gravity causes the liquid to go down, and the radiator fan and the movement of the vehicle push the liquid in the direction of the air movement.

Often, due to dirt and inaccessibility, the place of liquid leakage cannot be detected. Then certain measures must be applied in the process of detecting leak sources. Sometimes it is necessary to wash the engine under pressure using a degreasing agent to facilitate the search.

The inspection for fluid leakage should be thorough and well planned. During visual inspection, use a strong light source and a mirror for inaccessible places. Sometimes it is necessary to remove the protective covers and heat shields from the engine. Some leaks can only be seen when the engine is running, and some only when it is not running. Precautions are required when searching for moving parts when the engine is running. For some leaks, it is necessary to use fluorescent paints. When there are small leaks, after washing the engine or applying fluorescent paint, the client must drive the vehicle for several days for the liquid to leak.

Engine compartment inspection for fluid leakage

Sometimes you can only detect a leak by inspecting under the hood, and sometimes you need to inspect under the vehicle. Therefore, the search for liquid leaks can be divided into an inspection under the hood and an inspection under the vehicle.

To inspect for a leak under the hood, follow these steps:

Vehicle preparation

Ensure the vehicle for safe operation. Lift the hood cover and make sure it is secure. Remove all masks and elements that you think would interfere with the engine compartment for leaks.

Checking the cooling system for leaks

Check the radiator, radiator hoses, water pump, control valve, all connections, and hose manifolds.

Engine oil leak test

Check for oil leaks on the engine, oil cap, intake manifold, camshaft oil seal, and all other engine oil seals and gaskets.

Fuel leak test

Check for fuel leaks at the fuel supply and return lines, fuel filter connections, common rail, pressure regulator, injectors, and all other components in the fuel supply system located in the engine compartment under the hood.

Checking leakage power steering system

Check oil leaks on the power steering pump, oil tank, supply and return lines, and on the steering rack control box.

Checking for leaks in the brake system

Check for leaks on the brake fluid reservoir, brake hoses, connections, and on the rear brake master cylinder oil seal.

See also

Video recommendation

To inspect for fluid leaks under the vehicle, follow these steps:

Lifting the vehicle

Raise the vehicle in a safe manner and to a height that allows normal viewing under the vehicle. Remove the protective cover under the engine.

Checking the cooling system for leaks

Check for coolant leaks on the radiator, water pump, and engine block.

Check engine leak

Check for engine oil leaks on the engine block, crankcase, oil drain plug, oil filter, oil pressure switch, crankshaft oil seals, and other joints and seals on the engine.

Fuel leak test

Check for fuel leaks at the fuel supply hoses and connections, the fuel filter, and the engine block.

Check for leaks on the rack

Inspect the power steering pump, steering oil hose, rack, and oil leak on control system boxes.

Checking for leaks in the gearbox

Check the transmission, front and rear differentials for leaks, if any.