Radiator Pressure Cap for Infiniti Cooling System

Keep engine temperatures stable with this OE-style radiator filler cap ❄️. It seals the filler neck, holds factory-set pressure, and opens only when needed, protecting hoses, radiator, and heater core. Correct pressure raises the coolant’s boiling point and routes excess fluid to the overflow tank, then draws it back as the engine cools for a closed, clean cycle.

Why this part is needed

Without a tight, calibrated cap, the cooling system cannot build pressure. That leads to early boil-over, air pockets, and faster coolant loss—bad news for head gaskets, water pump, and plastic tanks.

How it works

A spring-loaded relief valve maintains the specified PSI to prevent overheating. A secondary vacuum valve pulls coolant back from the reservoir during cooldown. A high-temp seal ring and stainless plate resist corrosion and keep the system leak-free ♨️.

What happens if it’s broken

Expect overflow bottle bubbling, soft upper hose, sweet coolant smell, random temp spikes in traffic, or coolant stains around the neck. Ignore it and you risk warped heads, cracked tanks, and costly repairs.

Install and care tips

Only remove when cold. Inspect the neck, clean, and twist until it locks. Replace every 5–7 years or at the first sign of seal wear. Use fresh premix coolant and bleed air after service .

Compatibility

• Qx70/Fx
• Q70/M
• Q60/G Coupe
• Q70(201802-)Lam
• Qx50/Ex
• Q50
• Qx80/Qx56