How to Change the Coolant in a 2015 Husqvarna FE450HQ: Step-by-Step MotoSport Guide

Shop parts for a 2015 Husqvarna FE450HQ Dirt Bike.

Routine coolant changes are vital to keeping your 2015 Husqvarna FE450HQ running strong and protecting its high-performance engine from overheating and corrosion. Follow this proprietary MotoSport guide to safely and effectively change your coolant–and learn what makes the FE450HQ unique when it comes to maintenance.

What Makes the 2015 FE450HQ Coolant System Unique?

  • High-revving Engine: The FE450HQ is known for its robust 450cc engine that generates significant heat. Maintaining optimal coolant quality ensures consistent performance, especially during hard off-road riding.
  • Twin Radiator Setup: Like many Husqvarna enduro models, the FE450HQ uses dual radiators for improved cooling efficiency. Both sides must be flushed and refilled evenly for optimal results.
  • Aluminum Components: The cooling system uses lightweight aluminum. Always use coolant rated for use with aluminum engines to prevent internal corrosion.

Tools & Supplies You'll Need

  • Fresh pre-mixed motorcycle coolant (compatible with aluminum engines)
  • Basic hand tools (sockets, screwdriver)
  • Drain pan
  • Funnel
  • Clean shop towels
  • Distilled water (for flushing, optional but recommended)
  • Replacement sealing washer for drain bolt (recommended)
  • Protective gloves

Step 1 – Prepare the Bike

  • Ensure the engine is cool before starting.
  • Set the bike upright on a stand to keep it stable and level.
  • Remove any bodywork or radiator shrouds that block access to the radiators and cap.

Step 2 – Drain the Old Coolant

  • Place a drain pan under the water pump area.
  • Loosen and remove the coolant drain bolt, usually found at the lowest point of the water pump cover.
  • Remove the radiator cap to allow the system to drain fully. Let all coolant run out from both radiators. Dispose of old coolant safely–it is toxic.

Step 3 – Optional: Flush the Cooling System

  • Reinstall the drain bolt temporarily. Fill the system with distilled water.
  • Start the engine and run it for a short time (no more than a minute). Shut off and allow to cool.
  • Remove the drain bolt again; drain the water completely. Repeat if coolant appeared dirty.

Step 4 – Refit Drain Bolt

  • Install a new sealing washer on the drain bolt for leak-free performance.
  • Tighten the bolt to specification, avoiding over-torquing on the aluminum cover.

Step 5 – Add Fresh Coolant

  • Slowly pour new coolant into the radiator neck until full. Pour in small increments to minimize air pockets in the twin radiators.
  • Squeeze radiator hoses gently and rock the bike side to side to help burp trapped air.
  • Top up as the level drops, then fill the overflow reservoir to the "upper" line.

Step 6 – Bleed Air from System – Critical for FE450HQ

  • Leave the radiator cap off and start the engine. Run at idle for 1-2 minutes, watching for bubbles as trapped air escapes.
  • Shut off, allow to cool, check coolant level, and top off if required.
  • Refit the radiator cap and all removed bodywork.

Step 7 – Final Checks

  • Start the engine again, monitoring for leaks and ensuring the temperature remains normal.
  • After the first ride, recheck coolant levels in both the radiator and reservoir and top off if necessary.

Additional Tips Specific to the 2015 FE450HQ

  • Fan activation: If your bike has a fan kit installed, verify it operates correctly after coolant service.
  • Maintenance interval: For high-performance use, inspect your coolant yearly and replace it every two years or after any evidence of overheating.
  • Use only compatible coolants: Avoid using automotive coolant with silicates–always use formulas designed for aluminum motorcycle engines.

Staying on top of your FE450HQ's coolant maintenance is one of the best ways to protect the engine and ensure flawless performance through every ride.

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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.