Engine Cooling Pressure Cap — Reliable Seal for Stable Temperatures

This OEM-grade radiator/coolant reservoir cap keeps your Subaru’s cooling system sealed and pressurized. It’s needed to hold factory-set pressure so coolant won’t boil early, ensuring steady operating temperature, strong cabin heat, and long water pump and hose life.

How it Works ❄️

A spring-loaded pressure valve locks in the correct PSI, raising the coolant’s boiling point. When pressure spikes, it vents safely to the overflow. A vacuum valve then pulls fluid back as the engine cools, preventing hose collapse and air pockets.

What If the Cap Fails

Expect overheating in traffic, coolant loss or boil-over, weak heater, hard hot restarts, and possible air in the system. A weak spring or cracked seal can also trigger steam at the neck and leave white crust on the filler area.

Pro Tips

• Replace if rubber is hard, cracked, or the spring feels loose.
• Only remove when fully cold; check filler neck for debris.
• Match the pressure rating to the factory spec for best results.

Compatibility

• Tribeca