How to Change the Coolant in a 2018 Honda CRF450RX
Shop parts for a 2018 Honda CRF450RX Dirt Bike.
Routine maintenance on your 2018 Honda CRF450RX ensures maximum performance on and off the track. One critical step is changing the engine coolant–an easy process that keeps your engine running at optimal temperature and protects it from corrosion. Here is MotoSport.com‘s unique step-by-step guide tailored specifically for your model:
Why Change the Coolant?
Your CRF450RX should have its coolant replaced every 2 years or as specified in your maintenance schedule. Dirt, mineral buildup, or degraded coolant can cause overheating and significant engine wear.
What You Need
- Silicate-free premixed coolant (or distilled water to mix with concentrate)
- 8mm and 10mm sockets, a ratchet, 5mm Allen key
- Phillips screwdriver
- Small drip pan
- Funnel
- Replacement drain bolt washer (copper or aluminum)
- Shop rags/paper towels
- Torque wrench
Step 1: Ensure Safety
- Make sure the bike is completely cool before starting. Never open the radiator cap on a hot engine.
- Put the bike on a stand and remove the seat for easier access.
Step 2: Remove Necessary Body Panels
- Remove the seat if needed for access.
- Take off the radiator shrouds by removing the mounting bolts/Allen screws on the left side. The right-side plastic may require extra clips or screws to be released.
Step 3: Drain the Old Coolant
- Locate the water pump drain bolt along the bottom of the right engine case (typically 8mm).
- Position your drain pan underneath and remove the bolt to let coolant flow out.
- For best drainage, remove the radiator cap (You may have to use a Phillips screwdriver to remove the set screw securing it).
- Let coolant drain fully. Remove and inspect the crush washer–if worn, replace.
Step 4: Reinstall the Drain Bolt
- Fit a new washer if necessary.
- Torque the drain bolt to 10 Nm (7 lbfft) per Honda specification.
Step 5: Fill the Radiator with Fresh Coolant
- Using a funnel, slowly add silicate-free coolant to the radiator neck until it reaches the top.
- Gently rock the bike or squeeze radiator hoses to help release trapped air.
Step 6: Bleed the System
- Replace the radiator cap and start the engine for 1–2 minutes—do not let it get hot, just enough to circulate the coolant.
- Shut off the engine, let it cool, and recheck coolant level. Top off if needed.
Step 7: Reinstall Panels and Clean Up
- Reinstall plastics and radiator guards in reverse order of removal.
- Double-check for leaks and proper hose routing–especially the overflow line.
2018 CRF450RX Model Notes
- This model is engineered for both enduro and cross-country racing–cooling capacity is vital when riding low-speed trails or in hot climates.
- Always use coolant designed for aluminum radiator systems (silicate-free with corrosion inhibitors).
- If you ride extrema off-road or in muddy conditions, check your radiator fins regularly for clogging, as this will significantly reduce cooling efficiency.
Final Tips
- Used coolant is toxic–dispose of it according to local regulations.
- Check for leaks after your first few rides and recheck fluid level.
- Keep an eye on your engine temperature indicator if equipped.
MotoSport is your trusted source for CRF450RX parts and maintenance supplies. Stay ahead on maintenance to keep your ride reliable and race-ready.
Related Shopping Categories
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Shop Radiator Hoses for a 2018 Honda CRF450RX 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.