How to Change the Coolant in a 2018 Honda CRF250L RALLY ABS

Shop parts for a 2018 Honda CRF250L RALLY ABS Dirt Bike.

Routine maintenance is essential to keep your 2018 Honda CRF250L RALLY ABS running at its best, and changing the coolant is a critical part of this process. Honda recommends replacing the coolant every two years or 24,000 miles, whichever comes first. This helps prevent corrosion, ensures proper cooling, and maximizes engine longevity. Here’s everything you need to get the job done safely and efficiently.

What You’ll Need

  • Silicate-free coolant - use a 50/50 premixed antifreeze with corrosion inhibitors
  • 10mm and 8mm sockets
  • 5mm Allen key
  • Phillips-head screwdriver
  • Funnel
  • Drain pan
  • New single-use crush washer for the drain bolt
  • Paper towels and gloves

Step-by-Step Instructions

  1. Let the bike cool completely. Never open the radiator cap while the engine is hot–pressurized fluid can cause burns.
  2. Remove bodywork for access.
    • On the left (radiator) side, remove the upper 5mm Allen screw to loosen the plastics.
    • On the right side, remove four screws plus two plastic retainers to clear access to the radiator cap and overflow tank. Keep track of all fasteners.
    • Remove the two bolts holding the coolant reservoir with a 10mm socket. Some models with aftermarket skid plates may require additional removal of 4mm Allen bolts.
  3. Remove the radiator cap.
    • Use a Phillips screwdriver to remove the cap’s retaining screw, then lift off the radiator cap. Removing the cap helps the old coolant drain faster by allowing airflow.
  4. Drain old coolant.
    • Position a drain pan below the coolant drain bolt, usually located at the bottom of the right side of the engine (often marked with an arrow).
    • Use an 8mm socket to remove the coolant drain bolt. Allow the coolant to drain completely.
    • Also, drain the overflow tank by removing it or using a syringe and small tube to extract old coolant.
  5. Replace the crush washer on the drain bolt, then reinstall and torque it to spec.
  6. Flush the system (optional, but recommended).
    • Fill the system with distilled water, reinstall the cap, run the engine briefly, then repeat the drain process. This helps remove residue or contaminants.
  7. Add new coolant.
    • Insert a funnel into the radiator filler neck and slowly pour in new coolant until full. Fill the overflow tank to the “Full” line.
  8. Bleed air from the system.
    • Start the engine and let it idle briefly with the radiator cap off. Watch for air bubbles to escape as the coolant circulates.
    • Top off coolant as necessary, then install the radiator cap and re-secure with the set screw.
  9. Reassemble bodywork in reverse order, ensuring all hardware and fasteners are secure.
  10. Check fluid levels after your next ride. Top off if necessary, as some bubbles may work their way out after cooling and heating cycles.

Model-Specific Notes for the 2018 CRF250L RALLY ABS

  • This model features ABS (Anti-lock Braking System)–take care not to damage wheel sensors or wiring when removing side plastics.
  • Do not mix different types or brands of coolant-always use a silicate-free formula approved for aluminum radiators and Japanese motorcycles.
  • Be sure to install a fresh crush washer on the drain bolt to prevent coolant leaks.
  • The CRF250L RALLY has larger fairings than the standard CRF250L, which may require additional care when removing side plastics-avoid cracking tabs or misaligning grommets during reassembly.

Changing your CRF250L RALLY ABS’s coolant at the recommended interval protects your engine from overheating and corrosion, especially during technical riding or high desert travel. Take your time, double-check your work for leaks, and enjoy confident miles ahead.

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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.