Parts for your 2002 Toyota Caldina-Radiator cap

2002 Toyota Caldina radiator cap – what it does and when to replace it

Yes, the 2002 Toyota Caldina uses a radiator cap. This is supported by Toyota’s own technical publications: the Caldina T24-series Repair Manual (Cooling System section) includes a “Radiator Cap” test/inspection, the Toyota Electronic Parts Catalogue (EPC) lists “Cap, Radiator” for ZZT241/AZT241/ST246 variants, and the New Car Features guide for this series describes a pressurised cooling circuit. Typical spec is a 1.1 bar (approx. 108 kPa) cap, with the cap location on the top tank of the radiator under the bonnet. An unpressurised overflow bottle sits nearby.

The radiator cap isn’t just a lid. It’s a calibrated pressure valve that lets the cooling system run at a higher pressure so the coolant’s boiling point is raised, which helps stop overheating on hot Aussie and Kiwi days or long motorway climbs. It also manages coolant expansion and contraction: when things heat up, the cap lets excess coolant move to the overflow bottle, when things cool down, it draws coolant back in so the system stays topped up and free of air.

As part of routine servicing on a 2002 Caldina, the cap deserves a quick check. Make sure the rubber seals aren’t cracked or flattened, the spring feels firm, and the tangs lock securely. A workshop can pressure-test the cap, if it can’t hold the specified pressure or the vacuum valve sticks, it’s time for a new one. In local conditions, replacing the cap every 4–5 years or 80–100,000 km is cheap insurance, especially if the car tows, sees lots of stop–start, or runs a turbo ST246.

Only open the cap when the engine is stone cold. Use a rag, press down, and twist slowly to release any residual pressure. After removal, check the neck for corrosion and clean it up before refitting. When topping up, use the correct Toyota red/pink ethylene-glycol coolant specified for the engine, and bleed any trapped air per the service manual procedure.

• Symptoms of a tired cap: coolant pushing out into the bottle and not returning, frequent low coolant, overheating at low speeds, collapsed radiator hoses after cool-down, or crusty deposits around the filler neck.
• If originality matters, match the pressure rating stamped on the old cap or confirm via the EPC by engine code.

Technical sources referenced: Toyota Caldina T24 Series Repair Manual (Cooling System, Radiator Cap inspection), Toyota Electronic Parts Catalogue (Group 16 – Radiator & Water Outlet: Cap, Radiator), Toyota New Car Features (Caldina T24 cooling system overview).

Popular questions

What pressure rating is the 2002 Caldina radiator cap?
The factory spec is typically 1.1 bar (about 108 kPa). Always check the stamping on your existing cap or verify by engine code in the Toyota EPC to be sure you’re matching the correct rating for your variant.

Where is the radiator cap on a 2002 Caldina?
It’s on the top of the radiator under the bonnet, usually on the right-hand side when facing the car. The nearby plastic bottle is an overflow reservoir and is not pressurised.

How often should the radiator cap be replaced?
Inspect at every service, replace if it fails a pressure test, the seals are perished, or as preventive maintenance every 4–5 years or 80–100,000 km, especially if the vehicle tows or runs hotter conditions.