Parts for your 2009 Honda Elysion-Radiator cap

2009 Honda Elysion radiator cap — fitment, purpose and easy servicing advice

Technical sources confirm the 2009 Honda Elysion does use a conventional radiator pressure cap mounted on the radiator filler neck. This is documented in the Honda Elysion (RR1–RR4) Workshop/Service Manual under Cooling System – Radiator Cap Inspection/Testing (notes a 1.1 bar spec), reflected in Honda’s Electronic Parts Catalogue listing for a 1.1 bar radiator cap (commonly CAP, RADIATOR 19045-PAA-A01) for Elysion variants, and reinforced by the Elysion Owner’s Manual safety cautions about only opening the radiator cap when the engine is cold. So, a radiator-cap is relevant and fitted to the 2009 Honda Elysion.

On the 2009 Honda Elysion, the radiator cap is a small but mighty bit of kit. It seals the cooling system and holds a set pressure (about 1.1 bar/108 kPa), which raises the coolant’s boiling point so the van can handle Aussie and Kiwi summer heat and heavy loads without boiling over. When pressure climbs, the cap lets a little coolant move to the overflow bottle, as things cool, it draws coolant back in to keep the system topped up. That one valve manages expansion, contraction and pressure — neat and tidy under the bonnet.

As part of routine servicing, the radiator cap deserves a look. If the spring’s tired or the rubber seals are cracked, pressure control goes out the window and the Elysion can run hot, push coolant out, or suck in air. A quick visual check for perished rubber, crusty deposits or a bent sealing surface is worth doing at every service. If there’s any doubt, caps are inexpensive and easy to replace — no dramas.

Best practice for this model is to stick with a 1.1 bar cap that matches Honda’s spec. Mixing pressure ratings can be trouble: too low and it may boil early, too high and you risk stressing hoses, the radiator or heater core. Many techs swap the cap preventatively every 4–5 years or around 80–100,000 kilometres, or sooner if there are symptoms like coolant loss, gurgling after shutdown, collapsed upper hose when cold, or intermittent overheating.

When removing the cap, only do it stone-cold, even warm is risky. Crack the cap to the first stop to vent pressure, then remove. After fitment, run the engine with the heater on and bleed any air as per Honda procedure. If the cooling system’s being serviced — fresh Type 2 coolant, new thermostat or hoses — pairing that with a fresh, correct-spec cap keeps the Elysion happy and running cool.

• Symptoms of a dodgy cap: coolant stains around the neck, frequent top-ups, erratic temp gauge, or hoses that collapse after cooldown.
• What to buy: 1.1 bar cap, OE-equivalent quality, clean sealing faces on install.
• Service tip: Inspect every service, replace on condition or time/kilometres.

Popular questions about 2009 Honda Elysion radiator caps

What pressure rating does the 2009 Honda Elysion radiator cap use?
The Elysion uses a 1.1 bar (108 kPa) radiator cap. That rating balances boiling protection with component longevity. Sticking to the Honda-spec pressure avoids early boil-over (if too low) or undue stress on the cooling system (if too high).

Where is the radiator cap on a 2009 Honda Elysion?
It’s on the radiator filler neck under the bonnet, typically near the upper radiator hose. It’s not on the overflow bottle — that bottle is non-pressurised. Pop off any plastic trim cover if fitted, and only open the cap when the engine is fully cold.

How often should the radiator cap be replaced?
Inspect at every service and replace every 4–5 years or 80–100,000 km, or immediately if there are signs of wear, coolant loss, or overheating quirks. Given the low cost and big role it plays, preventative replacement is cheap insurance.