Parts for your 2018 Toyota C-hr-Radiator cap

2018 Toyota C‑HR radiator cap: what it does and how to look after it

Based on Toyota’s technical documentation, the 2018 Toyota C‑HR is fitted with a radiator cap (radiatorcap). The Toyota Repair Manual for C‑HR (ZYX10/NGX10) lists a “Radiator Cap Sub‑Assembly” in the Cooling System components, and the Toyota Electronic Parts Catalogue shows a Cap Sub‑Assy, Radiator for 2018 C‑HR variants, typically rated at 108 kPa (1.1 bar). The AU/NZ Owner’s Manual also cautions against removing the radiator cap when hot—clear evidence the part is present and relevant.

On the 2018 C‑HR, the radiator cap is a small but essential pressure valve. It seals the cooling system and holds a set pressure so the coolant’s boiling point is raised, helping the 1.2‑litre turbo or hybrid engine keep its cool on hot Aussie and Kiwi days and long motorway climbs. It also manages coolant flow to and from the overflow bottle as the engine heats and cools, keeping air out and the system topped up.

For servicing, the cap deserves a quick once‑over whenever coolant is checked or replaced. Look for perished rubber seals, crusty deposits, or a sticky spring. If the cap can’t hold pressure, drivers may see slow overheating, collapsing hoses after cool‑down, or coolant pushing into the overflow and not returning. A healthy cap prevents those headaches.

Replacement is straightforward: always match the pressure rating (typically 108 kPa/1.1 bar for C‑HR, confirm on the cap label or via Toyota EPC) and choose a quality cap that’s compatible with Toyota Super Long Life Coolant (pink). If in doubt, use a genuine Toyota radiator cap sub‑assembly. There’s no fixed kilometre interval for caps, but an annual inspection is smart. Replace the cap if it fails a pressure test, any time the radiator is changed, or proactively after 8–10 years or high mileage.

1. Let the engine go stone cold.
2. Cover the cap with a rag, press down and turn anti‑clockwise to release.
3. Wipe the neck clean, check for nicks, and fit the new cap firmly.

Good habits help: keep the coolant at the correct level with the right Toyota SLLC (pink), never mix coolants, and address leaks early. With a sound radiator cap, the 2018 C‑HR’s cooling system stays pressurised, efficient, and ready for summer road trips.

Popular questions about the 2018 Toyota C‑HR radiator cap

What pressure rating does the 2018 C‑HR radiator cap use?

Most 2018 C‑HR models use a 108 kPa (1.1 bar) cap. Always confirm by reading the marking on the existing cap or checking the Toyota parts listing for the specific VIN, especially if the radiator has been replaced before.

Where is the radiator cap on a 2018 Toyota C‑HR?

It’s mounted on the radiator’s upper tank in the engine bay. On hybrids, there may also be a pressurised reservoir cap in the cooling circuit—treat both as hot‑zone components and only open when the engine is completely cool.

How often should the radiator cap be replaced?

There’s no strict interval. Inspect it at every service, test it at coolant change time, and replace it if the seal is cracked, the spring is weak, it fails a pressure test, or as preventative maintenance after 8–10 years or high kilometres.