How to Change the Coolant in a 2018 Sherco 250SEF-R: Step-by-Step Guide

Shop parts for a 2018 Sherco 250SEF-R Dirt Bike.

Properly maintaining your 2018 Sherco 250SEF-R ensures optimal engine temperature, long service life, and peak performance. Coolant replacement is essential, and while the 250SEF-R has a straightforward system, there are a few model-specific tips to keep in mind for this high-performance four-stroke dirt bike.

Tools & Supplies Needed

  • Fresh coolant (Minerva Perma Universal D 4 or equivalent, rated to -25°C)
  • Drain pan
  • 8mm and 10mm sockets
  • Ratchet and extensions
  • Funnel
  • New sealing washer for drain bolt (recommended)
  • Shop towels
  • Torque wrench (for reassembly)

Step 1 – Preparation

  • Let the engine cool completely before attempting service.
  • Stand the bike upright on a stable, level surface. This ensures a complete drain and accurate refill.
  • Remove the radiator cap (cap 1) to relieve any system pressure.
  • Place a drain pan beneath the coolant drain bolt located at the lower left side of the engine/radiator.

Step 2 – Draining the Coolant

  • Remove the coolant drain screw (screw 3) carefully. Allow all coolant to drain into your pan. Inspect for debris or oil, which may indicate contamination.
  • For best results, also remove the radiator bleed screw (M6x8, left side of radiator). This helps air escape and the system drain fully.
  • Properly dispose of the old coolant at a certified collection center. Coolant is toxic and cannot be poured down the drain.

Step 3 – Inspect and Flush (Optional)

  • Before refilling, inspect hoses, clamps, and the radiator for leaks or damage.
  • If the bike sees demanding use or the coolant was especially dirty, run a flush of distilled water through the system, then drain again.

Step 4 – Filling with New Coolant

  • Install a new sealing washer on the drain screw, then securely tighten the screw to 6Nm to prevent leaks.
  • Tighten the radiator bleed screw to 8Nm, but leave loose for initial filling to evacuate air.
  • Using a funnel, pour coolant into the radiator through the cap opening (cap 1). Allow coolant to run until you see it coming out of the bleed screw without bubbles, then tighten the screw with a fresh gasket.
  • Continue filling until the level indicator on the expansion tank reads full (approx. 1.1 liters for this model).
  • Replace and secure the radiator cap.

Step 5 – Bleed the System & Check Levels

  • Start the engine and let it idle. As the engine warms up, tilt the bike carefully left and right to help any last bubbles escape.
  • Shut off the engine, allow to cool, then double check and top up coolant if necessary. The level should be exactly at the "LEVEL" mark indicated on the expansion vessel.

Special Sherco 250SEF-R Notes

  • This model's robust cooling system is designed for aggressive trail & enduro usage. Consistent coolant changes safeguard the intricate water pump and aluminum radiator against corrosion and overheating.
  • Routinely check for weep hole leaks at the water pump; a leak may signal a seal issue that requires more extensive service.
  • OEM specification is Minerva Perma Universal D 4–25°C. Use only compatible coolants to prevent gasket and seal failure.

When to Change the Coolant

  • As a rule of thumb, service the coolant at least every 24 months or sooner if riding in demanding conditions or after deep mud/water crossings.
  • Inspect coolant color and clarity at every oil change for early detection of contamination or issues.

Regularly flushing & replacing coolant will keep your 2018 Sherco 250SEF-R running cool through every lap, trail, and adventure.

Related Shopping Categories

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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.