How to Change the Coolant in a 2008 KTM 105SX
Shop parts for a 2008 KTM 105SX Dirt Bike.
Maintaining your 2008 KTM 105SX includes regular coolant changes to keep your engine running cool and reliably on the track. Swapping the old coolant for new is a straightforward process, but there are crucial steps specific to the KTM 105SX to prevent air pockets and ensure long engine life. Here is the complete MotoSport guide to changing your 2008 KTM 105SX coolant, with key tips every owner should know:
What You Need
- Fresh, high-quality engine coolant suitable for off-road motorcycles (avoid pure water or automotive-only fluids)
- A catch pan for old coolant
- Socket or Allen wrench set
- Funnel (narrow tip helps)
- Clean rags
- Protective gloves and eyewear
Step-by-Step Coolant Change
-
Cool Down the Bike
Make sure your 105SX is cool to the touch before you begin. Opening a hot radiator can cause burns or injury. -
Access the Radiators
Remove your seat and side panels for easy access to both radiators and the cooling system components. -
Drain the Old Coolant
Place your catch pan under the right side of the bike.
Locate and remove the lower radiator drain bolt on the right radiator (usually near the base of the radiator housing). If no dedicated drain bolt exists, you may need to loosen the lower radiator hose clamp and disconnect the hose to drain all fluid.
Remove the radiator cap to allow the system to drain fully and quickly. -
Flush (Optional, for Thorough Maintenance)
If the old coolant appears dirty or contaminated, flush the radiators by pouring distilled water through the system, then drain completely.
Replace and tighten the drain bolt or hose. -
Refill with New Coolant
Pour approximately 0.5 liters of fresh coolant into the left radiator, then remove the bleed bolt (located at the top or on the right side of the right radiator). Slowly continue adding coolant until it flows bubble-free from the bleed bolt location. Immediately replace and secure the bleed bolt to avoid air reentering the system–air pockets can cause overheating.
Continue topping up coolant in the left radiator until fluid is roughly 10 mm above the radiator fins.
The total capacity for your KTM 105SX cooling system is 1 liter. -
Check for Leaks
Inspect all connections and the drain area for leaks. Tighten as needed. -
Bleed and Top Off
Briefly start the bike and let it idle until warm, allowing coolant to circulate.
After warming up, switch off and let the engine cool.
Recheck coolant level in the left radiator and top off if needed. -
Reinstall Panels and Clean Up
Replace side panels and seat, clean any spilled coolant from paint or plastics, and safely dispose of old coolant.
Key 2008 KTM 105SX Owner Reminders
- The KTM cooling system is sensitive to air pockets. Always use the bleed bolt and fill procedure to avoid hot spots and possible engine damage.
- Use only motorcycle-safe, silicate-free coolant to prevent water pump seal and gasket deterioration.
- Regularly inspect radiator hoses and the cap for cracks or wear. Replace if signs of wear appear.
- The manual recommends performing coolant changes yearly or as part of your normal racing maintenance schedule.
Changing the coolant on your 2008 KTM 105SX is a quick job, but critical for reliability on the track. Keep your system in top condition with the right service routine, and always use quality parts designed for your ride.
Related Shopping Categories
Shop Radiators for a 2008 KTM 105SX Dirt Bike.
Shop Coolant for a 2008 KTM 105SX Dirt Bike.
Shop Temperature Sensors for a 2008 KTM 105SX Dirt Bike.
Shop Tools for a 2008 KTM 105SX Dirt Bike.
Shop Radiator Hoses for a 2008 KTM 105SX 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.