Parts for your 2005 Honda Cr-v-Radiator cap

2005 Honda CR‑V radiator cap: purpose, fitment and service tips

Yes, the 2005 Honda CR‑V does use a radiator cap. Technical sources back this up: the Honda CR‑V 2002–2006 Service Manual (Cooling System) includes a “radiator cap inspection/test” using a pressure tester at 108 kPa (1.1 kgf/cm², 16 psi). Honda’s genuine parts catalogue lists a radiator cap for this model (commonly referenced as 19045‑PAA‑A01), and major application guides from aftermarket suppliers specify a 1.1 bar (16 psi) cap for the 2005 CR‑V. That means the radiator cap is very much relevant to this vehicle’s cooling system and routine servicing.

The radiator cap on a 2005 CR‑V does more than just close the filler neck. It’s a calibrated pressure valve that lets the cooling system safely run at around 1.1 bar, lifting the coolant’s boiling point so it can handle Aussie and Kiwi summer heat, towing, and long climbs without boiling over. When things cool down under the bonnet, the cap’s vacuum valve draws coolant back from the overflow bottle, keeping the system full and free of air. If the cap weakens or its seals get crusty, pressure control goes out the window and the engine can run hot, push coolant into the reservoir, or pull in air on cool‑down.

As part of regular servicing, it’s smart to inspect the cap at least yearly or every 20,000 km. Look for cracked or flattened rubber, corrosion on the seat, or a sticky spring. A workshop can pressure‑test the cap to the Honda spec (about 16 psi), if it doesn’t hold or release correctly, replace it. Always fit the correct 1.1 bar cap that meets Honda’s spec—cheap or wrong‑pressure caps can create hard‑to‑trace overheating or coolant loss. Replace the cap whenever you do major cooling system work, or if you’re changing to fresh Honda Type 2 (blue) premixed coolant.

• Only remove the cap when the engine is stone cold—wrap it in a rag and turn slowly to the first stop to vent any residual pressure.
• After refilling, top the radiator to the brim and set the overflow bottle to the MAX line, recheck levels after the first proper heat cycle.
• Watch for signs of a crook cap: unexplained coolant loss, a collapsed upper hose after cool‑down, gurgling into the bottle, or overheating in traffic.

Where is the radiator cap on a 2005 Honda CR‑V?

It’s on the radiator itself, near the top tank under the bonnet—typically on the passenger side. Don’t confuse it with the plastic overflow bottle cap, that one isn’t pressurised.

What pressure cap should be used?

A 1.1 bar (16 psi) cap that meets Honda’s specification is required. Genuine Honda (often referenced as 19045‑PAA‑A01) or an equivalent quality aftermarket cap with the same rating will do the job.

How often should the cap be replaced?

Have it inspected annually or every 20,000 km and tested with a pressure tool. Replace it if it fails testing, shows seal damage or corrosion, or as a preventative measure every few years—especially when doing coolant service.