Parts for your 2015 Toyota Crown-Radiator cap

2015 Toyota Crown radiator cap – what it does and how to look after it

Based on Toyota technical documentation for the S210-series Crown (Cooling System section of the Toyota Repair Manual and the Toyota Electronic Parts Catalogue), the 2015 Toyota Crown is fitted with a pressure-type radiator cap. Depending on engine variant, the cap sits on the radiator’s top tank or on an engine-side filler neck, hybrid models also have a separate cap for the inverter cooling loop. So a radiator cap absolutely is relevant on this vehicle.

The radiator cap’s job is simple but critical. It seals the system and holds pressure so coolant boils at a higher temperature, helping the Crown keep its cool on long Kiwi and Aussie drives. Inside the cap is a spring-loaded pressure valve and a smaller vacuum valve. When system pressure climbs, the cap lets a little coolant push across to the overflow bottle. As things cool down, the vacuum valve draws coolant back, preventing hoses from collapsing and keeping air out.

For servicing, the cap deserves a quick check any time the coolant is inspected or replaced. Toyota typically specifies a cap in the 1.1–1.3 bar range for S210 Crown variants, always match the rating on the original or the owner’s manual. Using an under-rated cap can lead to boil-over, over-rated can stress the radiator and hoses.

• Inspect annually or every 20,000 km: look for cracked rubber seals, a weak or sticky spring, corrosion on the sealing surfaces, and crusty deposits.
• Pressure-test if in doubt: a workshop can test the cap with a hand pump, replace if it won’t hold the specified pressure or won’t release smoothly.
• Replace proactively at coolant service intervals: many owners swap the cap when changing Toyota Super Long Life Coolant (pink) to avoid niggling cooling issues.
• Safety first: never open the cap hot. Wrap a rag around it and release slowly once the engine is completely cool.
• Fit quality: use a genuine or high-quality cap with the correct depth and pressure rating. Clean the filler neck before refitting.

Signs the Crown’s cap may be past it include repeated coolant loss with no visible leaks, hoses that go flat after cooling, overheating under load, or a reservoir that overflows and doesn’t draw back. A fresh, correctly rated cap is inexpensive insurance for the V6, four-cylinder, or hybrid variants alike.

Popular questions about the 2015 Toyota Crown radiator cap

Where is the radiator cap on a 2015 Toyota Crown?

On most S210 Crowns it’s either on the radiator’s top tank or on a metal filler neck near the engine’s upper radiator hose. Hybrid versions also feature a separate cap on the inverter coolant reservoir, which is a different circuit from the engine cooling system. Check under the bonnet for the warning label and the cap with the pressure rating stamped on top.

What pressure rating should the cap be?

Toyota commonly uses caps around 1.1 bar on passenger models of this era, but owners should match the exact rating shown on the existing cap or in the owner’s manual. The correct rating maintains the designed boiling point and protects hoses, the radiator, and heater core from excess stress.

How often should it be replaced?

Have the cap inspected at each service and replaced at the first sign of seal wear, corrosion, or weak spring tension. Many workshops recommend renewing it alongside coolant changes (often around 5 years/100,000 km for Toyota Super Long Life Coolant) to keep the cooling system reliable.