How to Change the Coolant in a 2021 Husqvarna TC85

Shop parts for a 2021 Husqvarna TC85 Dirt Bike.

Keeping your 2021 Husqvarna TC85's cooling system in top shape is key to maximizing engine performance and longevity. Coolant degrades over time–especially after intense riding or races–so regular replacement is crucial. The TC85 uses a dual-radiator system engineered for serious racing, and proper maintenance ensures your two-stroke keeps running cool, no matter the challenge. Follow this MotoSport guide for a safe, thorough coolant change.

Required Tools & Supplies

  • Fresh, high-quality motorcycle coolant (consult your manual for approved types and capacities)
  • Clean catch pan
  • Socket set or wrench (commonly an 8mm or 10mm)
  • Flathead screwdriver
  • Funnel
  • Clean rags
  • Safety gloves and eye protection

Step-by-Step Process

  • Ensure safety: Work only when the engine is cool to prevent burns. Stand the bike securely on a stand.
  • Remove the radiator cap: Unscrew the radiator cap to relieve pressure. This also allows coolant to drain freely.
  • Locate the coolant drain bolt: On the TC85, the coolant drain bolt is typically located at the base of the water pump on the right engine case. Position your drain pan below this bolt.
  • Remove the drain bolt: Using your socket or wrench, slowly loosen and remove the drain bolt. Allow coolant to flow completely into the pan. Some models may also have a drain plug or hose at the bottom of each radiator for even more thorough draining.
  • Flush (optional, but recommended): For a more thorough flush, temporarily reinstall the drain bolt, fill the radiator with distilled water, and briefly run the engine for 30–60 seconds. Turn off the bike, let it cool, and repeat the drain. This flushes residues and debris from both radiators.
  • Reinstall and torque the drain bolt: Clean the bolt and the sealing surface. Reinstall the bolt and tighten securely (refer to your owner's manual for torque specs–generally around 10–12 Nm).
  • Refill with new coolant: Pour coolant slowly into the radiator filler neck. The TC85's radiators are interconnected, so be patient as the coolant fills both sides. Watch for air pockets.
  • Bleed the system: Many TC85 models have a bleeder screw on the cylinder head. Loosen this screw slightly while topping off coolant until a steady stream (no bubbles) comes out, then retighten. This step is important to prevent trapped air, which can cause overheating .
  • Top off the coolant: Add coolant until it reaches the bottom of the filler neck. Replace and secure the radiator cap.
  • Run and re-check: Start the engine and let it idle until it reaches normal operating temperature. Shut down, let it cool, and check the coolant level again. Top up if necessary.
  • Check for leaks: Inspect the drain bolt, each radiator, and the hoses for leaks while the bike is running and after shutdown.

Model-Specific Tips for the TC85 Owner

  • The 2021 TC85 uses a lightweight aluminum radiator design for optimal cooling. Debris between the radiators or bent fins can reduce efficiency. Inspect and gently clean radiator fins when changing coolant.
  • Due to the TC85's two-stroke engine, always use a silicate-free coolant designed for motorcycles to avoid premature water pump seal wear.
  • Check for signs of oil contamination in your coolant–milky or oily coolant may indicate a faulty gasket or mechanical issue.
  • Factory torque specs for the drain bolt (typically 10–12 Nm) and radiator cap (tight, but do not overtighten) prevent leaks or damage.
  • Perform a coolant change at least once a year, or more often if you ride in muddy or sandy conditions.

Final Reminders

  • Dispose of used coolant properly according to local regulations.
  • Regular coolant changes and system inspections will help avoid sudden overheating or costly engine repairs.

Related Shopping Categories

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Shop Radiator Hoses for a 2021 Husqvarna TC85 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.