Parts for your 2016 Toyota Vitz|yaris-Radiator cap

2016 Toyota Vitz/Yaris radiator cap — what it does and how to look after it

According to Toyota’s Repair Manual and Electronic Parts Catalogue for the XP130-series Vitz/Yaris (2011–2019), the 2016 model is built with a pressurised radiator cap on the radiator neck. Toyota specifies a “Cap Sub‑Assy, Radiator” with a typical rating of 108 kPa (1.1 bar), so the radiator cap is absolutely relevant on this vehicle.

On the 2016 Vitz/Yaris, the radiator cap does more than just seal the filler neck. It holds precise pressure in the cooling system, lifting the coolant’s boiling point so it can manage Aussie and Kiwi summer temps without boiling over. As the engine cools, the cap’s vacuum valve draws coolant back from the overflow bottle, helping keep air out and maintaining consistent coolant volume. When it’s healthy, owners see stable temperature readings, a happy heater, and hoses that don’t collapse or balloon.

Because it’s a small part doing a big job, the cap deserves routine attention. A weak spring or perished seal can cause hard-to-trace dramas: slow overheating in traffic, coolant loss into the overflow with no visible leaks, crusty deposits around the filler neck, or a sweet smell under the bonnet. On a 2016 Vitz/Yaris, those symptoms often clear up with a fresh, correct-spec cap.

• Inspection: Check the cap at each service (about every 10,000–15,000 km). Look for cracked or flattened rubber seals, corroded seating surfaces, and sticky or weak spring action.
• Testing: A workshop can pressure-test the cap to the Toyota spec (around 108 kPa / 1.1 bar). Anything outside tolerance is a cue to replace.
• Replacement interval: Many owners replace the cap every 4–5 years or 80,000–100,000 km, or whenever the cooling system is serviced (radiator, hoses, thermostat).
• Safety: Only remove the cap when the engine is stone cold. Use a rag and press down while turning to control any residual pressure.
• Correct part: Stick to the specified pressure rating (1.1 bar). Higher-pressure caps aren’t an upgrade here and can stress hoses and the radiator.
• Coolant and hose checks: Ensure the overflow hose is snug and crack-free, and top up with Toyota Super Long Life Coolant (pink), premixed to the correct ratio.

A good radiator cap is cheap insurance for the 2016 Toyota Vitz/Yaris. Keep it in shape, and the cooling system will repay with stable temps and long component life.

What radiator cap pressure does a 2016 Toyota Vitz/Yaris use?

Most 2016 Vitz/Yaris models specify approximately 108 kPa (1.1 bar). Owners can confirm by reading the cap label or checking by VIN in the Toyota parts catalogue. Sticking to the correct rating helps protect hoses, seals, and the radiator.

How often should the radiator cap be replaced?

Have it inspected every service and consider replacement every 4–5 years or 80,000–100,000 km. Replace sooner if pressure test results are off-spec or if there are signs like coolant pushing into the overflow, temperature swings, or crusty deposits at the filler neck.

Where is the radiator cap on a 2016 Vitz/Yaris?

It’s mounted on the radiator neck at the top of the radiator. Only open it when the engine is completely cold to avoid burns or sudden coolant release.