Radiator hose Expansion tank for Volv o Radiator hose upper 31439561 Reservoir hose

Product Description:

Auto engine coolant recovery tank hose
OE NO.:   31439561  30792244

Applicable vehicle type: For Vol vo

Engine Coolant Reservoir Hose (abbreviated as ECRH, also commonly referred to as Coolant Overflow Hose/Reservoir Return Hose) is a core connecting component of the automotive cooling system. It is responsible for enabling bidirectional flow of coolant between the reservoir tank and the main circulation (radiator/engine) when the cooling system undergoes thermal expansion and contraction. This function maintains system liquid level and pressure balance, preventing engine overheating caused by coolant overflow or deficiency.

Core Functions:

• Thermal Expansion Overflow: As the engine operates and temperature rises, the coolant expands, increasing system pressure. Excess coolant flows through the hose into the reservoir tank, preventing the radiator cap from being blown open and causing leakage.
• Cold Contraction Reflux: When the engine stops and cools down, the coolant contracts, creating a negative pressure in the system. Coolant from the reservoir tank flows back through the hose into the main circulation, ensuring the system remains fully filled with coolant and preventing airlocks.
• Pressure Balance: In conjunction with the reservoir tank's vent, it stabilizes system pressure, reducing pressure impact on components such as the water pump and radiator, thereby extending component lifespan.

• 20 years of specialized auto parts industry experience
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