Description
This is a coolant system pressure cap that fits on the radiator or coolant reservoir neck. It seals the cooling system and maintains proper pressure so coolant does not boil, helping your engine run at a stable temperature. The cap contains a spring‑loaded valve that:
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Releases excess pressure into the overflow tank when hot
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Allows coolant to be drawn back into the system as the engine cools
✅ Keeps cooling system pressurized
✅ Prevents leaks and boiling
✅ Supports consistent engine temperature
✅ Protects radiator, hoses, and water pump
Common Applications / Fitment
This cap is used on many Nissan & Infiniti vehicles (depending on model/market), generally for models equipped with that radiator neck/coolant system design. Specific fitment depends on year and region.
Why It’s Important
If this cap fails, you may notice:
Overheating
Coolant leaks
Loss of cabin heat
Collapsed hoses after shutdown
Steam or boiling sounds from under the hood
