How to Change the Coolant in a 2012 Suzuki DRZ400S: Step-by-Step Guide

Shop parts for a 2012 Suzuki DRZ400S Dirt Bike.

Performing a coolant change on your 2012 Suzuki DRZ400S is essential to keep the bike running at optimum temperature and to protect the engine from overheating or corrosion. Below, MotoSport outlines a robust, proprietary process tailored for your DRZ400S, with model-specific notes every owner should know.

Why Change the Coolant?

Coolant breaks down over time, losing its ability to regulate temperature and resist corrosion. For the DRZ400S, especially when riding off-road or in hot conditions, a coolant flush every two years (or sooner if you ride hard) helps prevent internal damage and ensures reliable performance.

What You Need

  • 50/50 premixed motorcycle coolant (non-silicate, aluminum-friendly)
  • 12mm and 10mm sockets, socket wrench, Phillips screwdriver
  • Catch pan
  • Clean rags
  • Funnel
  • Rubber gloves (optional)

Preparation – DRZ400S-Specific Notes

The DRZ400S has a water pump access panel on the right side and its radiators are exposed, but always ensure the bike is completely cold before starting. On some DRZ400 units, there is a coolant bleed screw on the water neck, while others do notverify yours before starting.

Step 1: Remove Side Cover

Take off the right side plastic cover by removing the mounting bolts (12mm socket required). This allows clear access to the water pump and drain bolt.

Step 2: Remove Radiator Cap

Unscrew the small Philips screw that secures the radiator cap, then carefully remove the radiator cap itself. This will allow air in, helping the coolant drain more freely.

Step 3: Drain the Coolant

Locate the coolant drain bolt on the water pump cover (typically a 10mm hex bolt). Place a catch pan underneath, then remove the drain bolt. Coolant will flow outallow ample time for it to fully drain.

Step 4: Bleed the System (If Equipped)

If your DRZ400S has a coolant bleeder screw at the water neck (top front of the cylinder head), loosen it a few turns after draining. Some bikes may also have a bleeder on the left radiator. This helps release any trapped air. If your neck points straight up and there is no screw, skip this stepit means your model does not include this feature.

Step 5: Reinstall Drain Bolt and Begin Filling

Reinstall and snug the drain bolt. Begin refilling the right radiator slowly using a funnel. Fill until coolant appears from the water neck bleeder (if equipped), then tighten the bleeder. Keep slowly filling the radiator as needed, then do the same for the left radiator if a bleeder is present. Top off the right radiator again to ensure it is full.

Step 6: "Burp" the Cooling System

Gently lean the DRZ400S far left and right to help any trapped air bubbles escape. Top off with more coolant if the level drops.

Step 7: Replace Cap – Start Engine – Recheck

Reinstall the radiator cap. Start your DRZ400S and let it idle until it reaches operating temperature. Closely monitor the temperature to ensure it doesn't overheat. Shut off the engine and allow it to cool completely. Remove the radiator cap and check the coolant leveladd more as needed. For best results, add about 1 inch of coolant to the overflow reservoir bottle for proper expansion space.

Step 8: Reassemble Plastics & Ride

Secure the side cover and all bolts. Wipe away any spilled coolant. Check for leaks after your first ride.

DRZ400S Model Notes

The 2012 DRZ400S does not use a radiator thermostat, which means it can take a little longer to reach optimal temperature compared to street bikes. Always check for air-purging screws depending on your water neck orientation. Using the correct premixed coolant formulated for aluminum engines is crucial to prevent premature water pump or gasket wear.

Tech Tips

  • Never mix different coolant typesalways flush the system before changing brands or types.
  • Regularly check hoses and clamps when servicing the cooling system.
  • If you ride in particularly dirty or muddy terrain, inspect radiators for debris regularly to avoid overheating.

Related Shopping Categories

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Shop Radiator Hoses for a 2012 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.