Parts for your 2009 Honda Cr-v-Radiator cap

2009 Honda CR‑V Radiator Cap — What It Does and How to Look After It

Technical documentation confirms the 2009 Honda CR‑V uses a conventional, pressurised radiator cap fitted directly to the radiator. It’s a relevant, serviceable part of the cooling system—not a sealed, capless setup. This is supported by the Honda CR‑V service manual procedures for “Radiator Cap Inspection/Pressure Test” (3rd‑gen CR‑V, 2007–2011), the 2009 owner’s manual cautions about not opening the radiator cap when hot, and Honda’s parts catalogue listing of a 1.1 bar (approx. 16 psi) cap for this model year.

• Honda CR‑V 2007–2011 Service Manual: Cooling System—Radiator Cap inspection/pressure test (specification approx. 1.1 bar)
• 2009 Honda CR‑V Owner’s Manual: Cooling system warnings and cap handling instructions
• Honda Genuine Parts Catalogue: Radiator Cap (1.1) applicable to 2007–2011 CR‑V models

On the 2009 Honda CR‑V, the radiator cap does much more than just close the filler neck. It seals the cooling system and holds a set pressure—about 1.1 bar (16 psi)—which raises the coolant’s boiling point so the engine can run at the right temperature without boiling over. Inside the cap are two valves: one releases excess pressure by sending coolant to the overflow bottle as things heat up, and the other draws coolant back in as the engine cools. That two‑way action helps keep the system full and free of air, protecting the water pump, heater core, and head gasket.

As part of regular servicing, the radiator cap deserves a quick once‑over. Under the bonnet (engine cold only), check the cap’s rubber seals for nicks, flattening, or hardening, and make sure the spring isn’t weak. If there’s any crusty residue on the cap or filler neck, clean it off and inspect for pitting. A cap that can’t hold pressure can cause slow overheating in traffic, random coolant loss, weak cabin heat, or swollen hoses. A workshop can pressure‑test the cap to spec, if it fails, replace it.

Replacement is straightforward: use a quality, 1.1 bar cap that meets Honda’s spec. Many owners choose genuine Honda to match the original pressure rating. Fit the new cap to a clean filler neck, making sure it seats firmly to the second detent. After any cooling‑system work, bleed air properly and top up with the correct Honda Type 2 coolant (pre‑mix) to the recommended level in the overflow bottle. As a rule of thumb, inspect the cap at every service, and consider replacement around 5 years/100,000 km—or sooner if there are signs of leakage, overheating, or a failed pressure test.

• Safety tip: Never remove the radiator cap when hot. Wait until the engine is stone cold. Press down and turn anti‑clockwise to the first stop to vent any residual pressure before removing fully.

Popular questions about 2009 Honda CR‑V radiator caps

What pressure rating does the 2009 CR‑V radiator cap use?
The 2009 CR‑V uses a cap rated at roughly 1.1 bar (about 108–110 kPa, commonly labelled 16 psi). Sticking with the correct rating ensures the cooling system maintains the designed boiling point and flow characteristics.

How often should the radiator cap be replaced?
Have it inspected at each service and pressure‑tested if there are cooling complaints. Many technicians recommend replacement every 5 years/100,000 km, or immediately if the seal is damaged, the spring is weak, or it fails a pressure test.

Where is the radiator cap and how do you open it safely?
It’s on the top tank of the radiator under the bonnet. Only open it when the engine is completely cold. Press the cap down and turn anti‑clockwise to the first stop to release any lingering pressure, then turn further to remove.