How to Change the Coolant in a 2019 Honda CRF450R

Shop parts for a 2019 Honda CRF450R Dirt Bike.

Routine coolant changes are critical to maintain your 2019 Honda CRF450R–this model’s high-performance engine thrives on optimal temperature control. Over time, old coolant loses its effectiveness, risking overheating and component damage. This step-by-step MotoSport guide ensures your cooling system remains reliable for the track or the trail.

What You’ll Need

  • Fresh coolant (check your manual for type recommendations)
  • Socket set and basic hand tools
  • Drain pan
  • Funnel
  • Protective gloves and eyewear
  • Clean shop towels

Changing Coolant: Step-by-Step Guide

  1. Ensure the Bike Is Cool and Secure
    Begin with a completely cooled-down engine–removing the radiator cap on a hot motor will cause hot coolant to spray under pressure.
  2. Remove the Radiator Cap
    Find the radiator cap on the left side. Place a rag around the cap and slowly turn it to release any built-up pressure.
  3. Drain Old Coolant
    Locate the coolant drain bolt near the water pump on the right side of the engine case. Position a drain pan underneath, then remove the bolt and sealing washer. Allow all coolant to fully drain from both the radiator and crankcase.
    Tip: Tilting the bike slightly side-to-side helps evacuate any trapped fluid.
  4. Inspect Components
    Check the sealing washer; replace it if worn or damaged. Inspect hoses for cracks, clamps for tightness, and the radiator for fin blockages or leaks–the CRF450R is performance-tuned, so cooling system health is vital.
    Carefully check the water pump’s weep hole beneath the pump housing. Leakage here signals a worn seal that should be addressed promptly to prevent further engine risk.
  5. Reinstall Drain Bolt
    Clean the bolt and the area around the drain. Refit it with the washer and torque it to Honda’s spec (consult your CRF450R owner’s manual for precise torque values).
  6. Refill the Coolant
    Slowly pour fresh coolant into the radiator neck using a funnel. For the 2019 CRF450R, typical fill after draining is about 1.09 US qt (1.03 liter).
  7. Eliminate Air Pockets
    Leave the cap off, start the engine, and let it idle for a few minutes–this purges trapped air. Turn off and let cool, then top off coolant if it drops. Repeat until the level stabilizes beneath the radiator cap lip.
  8. Reinstall Radiator Cap
    Make sure the cap is clean and undamaged. Tighten securely–an improperly fitted cap can cause coolant loss and engine overheating.
  9. Check for Leaks and Test Ride
    Inspect hoses, drain area, and radiator for leaks with the engine idling. Take a short ride, then recheck coolant level and system again once the engine has cooled down.

Specific Notes for the 2019 CRF450R Owner

  • This model’s cooling capacity is designed for aggressive riding. On hot days or in tight terrain, monitor temperature frequently to prevent boil-over.
  • If you install aftermarket radiators, hoses, or higher-pressure caps, confirm compatibility with stock cooling passages and clearances.
  • Inspect the coolant temperature sensor crush washer and torque as specified–leaks here lead to overheating and potential sensor malfunction.
  • If coolant is found in the oil, or vice versa, do not run the bike. This can indicate a failed water pump seal needing immediate service.

How Often Should You Change Coolant?

Honda recommends changing the coolant every two years or sooner if you ride in harsh conditions or notice any contamination.

Final Tips

  • Always properly dispose of old coolant–it is toxic and must not be poured down drains or onto soil.
  • Consider using a radiator guard, especially for motocross or trail-riding; the CRF450R’s radiators are exposed and easily damaged.

Related Shopping Categories

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Shop Radiator Hoses for a 2019 Honda CRF450R Dirt Bike.

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.