How to Change the Coolant in a 2020 Suzuki DRZ400S: Step-by-Step Guide
Shop parts for a 2020 Suzuki DRZ400S Dirt Bike.
Routine coolant changes are crucial for keeping your 2020 Suzuki DRZ400S running cool on the trails and extending the life of the engine. This model uses a liquid-cooled engine, and a fresh coolant swap every two years or 8000 miles is the baseline for optimal protection – more often if you ride in harsh conditions or push your bike hard. The DRZ400S doesn't require specialized tools, but following a precise bleeding procedure is key to avoiding trapped air and overheating.
Supplies You Will Need
- Socket set (10mm and 12mm)
- Phillips/flat screwdriver
- Drain pan
- Rags or shop towels
- New coolant (ethylene glycol-based, pre-mixed 50/50 is most convenient)
- Distilled water (if flushing system)
- Rubber gloves (optional for protection)
Coolant Change Procedure for 2020 DRZ400S
- Preparation: Make sure the bike is cold. Place the DRZ400S on a stand or level surface. Remove both side panels for easier access. Remove the radiator cap screw and then the radiator cap.
- Draining the Old Coolant: Locate the coolant drain bolt on the water pump cover (right side of the engine, 10mm bolt) and position a drain pan beneath it. Remove the drain bolt and let the old coolant flow completely. Remove the radiator cap if you haven't already to speed up draining. Dispose of old coolant responsibly.
- Optional Flushing: If the coolant is contaminated, flush the system with distilled water. Reinstall the drain bolt, pour in distilled water, idle the engine briefly, then drain again.
- Bleeding the System: The DRZ400S uses bleed screws at the top of the left radiator and on the water neck (at the cylinder head). Loosen both of these with a socket or screwdriver but do NOT remove them completely.
- Refilling with New Coolant: Slowly pour fresh coolant into the right radiator. As you fill, air will escape from the loosened bleed screws. Keep filling until coolant dribbles out steadily from each bleed screw; snug each one down as soon as coolant appears.
- Working Out Air Bubbles: With both radiators topped off, tilt the bike far left and right (while steady on its wheels) to help release any trapped air. Top off coolant if the level drops. Reinstall the radiator cap securely.
- Final Steps: Start the bike and let it idle for 3-5 minutes, monitoring the temperature and coolant levels. Shut off the engine, allow it to cool, then remove the radiator cap to top off as needed. Add about 1 inch of coolant to the overflow bottle.
- Check for Leaks: Wipe down any spilled coolant, check all bolts, and inspect for leaks around the pump and radiators.
- Reinstall Bodywork: Replace the side panels.
DRZ400S Model-Specific Tips & Warnings
- No Thermostat or Bleed Screw: Some DRZ400S bikes do not have a thermostat or a top water neck bleed screw. If your model's water neck points straight up, skip that bleed screw step—just use the left radiator screw.
- Air Bleeding is Critical: This engine is sensitive to trapped air, which can cause overheating. Bleed both locations thoroughly, tilt the bike as described, and top off after the first heat cycle.
- Coolant Overflow: Always maintain coolant above the MIN line in the overflow bottle. If the system percolates or pushes out coolant after a ride, recheck for trapped air.
- Use the Right Coolant: Always use a motorcycle-rated coolant. Premixed 50/50 types are ideal for quick changes and safe aluminum compatibility.
Conclusion
Changing coolant in the DRZ400S is simple but requires attention to the unique air bleed process and the absence of a thermostat in some models. Keep an eye on coolant levels after rides, and if you ever have issues with overheating, check for air in the system. For all the high-quality parts and supplies you need for your next coolant service, shop MotoSport—we have your DRZ400S covered.
Related Shopping Categories
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Shop Radiator Hoses for a 2020 Suzuki DRZ400S 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.