How to Change the Coolant in a 2018 Honda CRF450R

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Maintaining your 2018 Honda CRF450R is crucial for performance, longevity, and reliability. A coolant change is a fundamental part of dirt bike maintenance – if neglected, it can lead to overheating and serious engine damage. Here’s a robust step-by-step guide, specifically tailored to your model, so you can keep your CRF450R operating at peak temperature.

Everything You Need

  • Fresh coolant – use motorcycle-specific or the recommended glycol-based coolant
  • Distilled water (if using concentrated coolant)
  • Screwdriver or socket set for radiator cap and plastics
  • Drain pan
  • Replacement copper washer for the drain bolt (recommended)
  • Torque wrench
  • Work gloves & eye protection
  • Clean rags

Step 1: Prepare the CRF450R

  • Ensure the bike is completely cool. Never open the radiator cap or service the cooling system when the bike is hot – the system is under pressure and can spray scalding coolant.
  • Position the bike upright on a stand in a well-ventilated area.
  • If needed for access, remove the engine guard using a socket wrench. Note the torque for reinstalling guard bolts is 10 N·m.

Step 2: Drain the Old Coolant

  • Place a drain pan directly below the water pump (found on the right side of the engine's lower area).
  • Remove the radiator cap first to allow free draining.
  • Using the correct socket, remove the coolant drain bolt located at the bottom of the water pump. Allow all coolant to drain fully.
  • Inspect the copper washer on the drain bolt. Replace it if damaged, as a fresh seal prevents leaks.

Step 3: Reinstall the Drain Bolt

  • Reinstall the drain bolt with the copper washer in place. Torque the bolt to 10 N·m as per Honda's spec.

Step 4: Flush the System (Optional but Recommended)

  • If your previous coolant looked contaminated, flush the system. Slowly pour distilled water into the radiator, reinstall the cap, then start and briefly idle the engine. Turn off, let cool, repeat the drain step above.
  • Continue until drained water runs clear. Do not overfill during flushing – there's no need to run the engine hard.

Step 5: Refill with Fresh Coolant

  • Using a funnel, pour new coolant into the radiator – fill to the bottom of the filler neck (not all the way to the top).
  • If using concentrated coolant, always dilute with distilled water as per coolant bottle instructions.
  • Reinstall the radiator cap securely – improper installation can cause loss of coolant and severe overheating.

Step 6: Bleed the System of Air

  • Start the bike and let it idle for a few minutes to circulate coolant throughout the system.
  • Shut off the engine and allow to cool for several minutes. Remove the radiator cap and check the level – top up if needed.
  • Repeat the start/cool/check routine until the level remains steady.

Step 7: Inspection and Final Checks

  • Check for leaks around the drain bolt, hoses, water pump, and radiator seams.
  • Ensure the radiator overflow hose is routed correctly and the system is free of trapped air.
  • Inspect radiator fins for clogging and confirm the water leakage check hole under the water pump is dry – leaks here may indicate a failed seal.
  • Reinstall the engine guard if removed. Make sure all panels and connectors are secure.

Coolant Capacity Reference

  • When changing coolant: Approx. 1.03 liters (1.09 US qt).
  • After major engine disassembly: Approx. 1.12 liters (1.18 US qt).

2018 CRF450R Model Notes

  • This model’s drain bolt is accessible without removing major components – making coolant changes quick and easy.
  • Always use fresh coolant at least once per season, or more for hard racing conditions. Store bikes with the cooling system full.
  • If you experience recurring coolant loss, check your bike’s radiator cap for proper pressure rating – a weak spring can cause overboiling.

With proper coolant maintenance, your 2018 Honda CRF450R will stay cool under pressure whether you’re hammering motos or out for a weekend trail ride.

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Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.