The EF7 water pump inlet O-ring, with a dimensional accuracy of one hundredth of a millimeter (in accordance with the strict standards of the production line), is responsible for sealing the connection point of the connecting pipe to the water pump.
Due to the high temperature of the EF7 engine and the high pressure in the cooling circuit, this O-ring is manufactured from advanced material that is resistant to antifreeze chemicals and severe temperature changes to prevent the coolant level from dropping and air from entering the system.
Using this quality part from the production line supplier minimizes the risk of hidden leaks and heavy engine repair costs caused by overheating.

Technical note:
Due to the location of this O-ring, its leakage is usually difficult to see and causes a gradual decrease in radiator water; therefore, it is mandatory to replace this O-ring every time the water pump is replaced or the connecting pipes are opened.

Identifying the location of an oil leak:
Symptoms:
Water or antifreeze leaking from the water pump connection to the engine block
Continuously decreasing radiator water level without apparent leaks from the hoses
Grease and wetting around the water pump (a combination of water and antifreeze deposits)
Increased engine temperature due to a decrease in the coolant level