How to Bleed & Replace Brake Fluid on a 2018 Suzuki King Quad 400FSi 4X4 AUTO

Shop parts for a 2018 Suzuki King Quad 400FSi 4X4 AUTO ATV.

This MotoSport guide shows how to safely and effectively drain, flush, and bleed the hydraulic brake system on a 2018 Suzuki King Quad 400FSi 4X4 AUTO (MMY: SUZUKI;KINGQD4FSI;2018). Follow these steps precisely. Use only DOT 3 or DOT 4 brake fluid as specified by Suzuki, and dispose of old fluid responsibly.

Tools & Supplies

  • DOT 3 or DOT 4 brake fluid (fresh, unopened)
  • Brake bleeder wrench or appropriately sized box wrench
  • Clear tubing to fit bleeder nipples
  • Catch bottle or container
  • Turkey baster or fluid syringe (optional)
  • Clean lint-free rags and isopropyl alcohol
  • Torque wrench (for caliper & bleeder torque checks)
  • Jack or ATV stand and wheel chocks
  • Assistant for manual pedal/lever bleeding (optional if using vacuum or pressure bleeder)

Important Notes Specific to the 2018 King Quad 400FSi

  • The King Quad 400FSi uses a combined hydraulic system with separate front and rear calipers but shared master cylinder layout; bleeding order matters to avoid trapped air.
  • Front brake calipers are single-piston units; rear is typically single-piston as well. Bleed each caliper individually.
  • ABS is not fitted on this model, simplifying bleeding sequence.
  • Park mode/automatic transmission offers no special brake-bleeding procedure beyond standard safety: ensure ATV is stable and transmission is in Park with parking brake engaged or wheels chocked.
  • Brake fluid can damage paint and plastics — protect finishes and clean spills immediately with alcohol.

Safety & Prep

  • Work on a flat level surface. Chock wheels and disconnect battery negative terminal if you will be working near electrical components.
  • Wear gloves and eye protection. Brake fluid is corrosive to paint & skin.
  • Keep the master cylinder reservoir cap closed except when topping up to avoid contamination.

Bleeding Sequence

Bleed calipers in order of furthest from the master cylinder to nearest. On this model the recommended sequence is:

  1. Rear axle caliper (furthest rear)
  2. Front right caliper
  3. Front left caliper (closest to master cylinder)

Step-by-Step: Full Fluid Replacement

  1. Remove dirt and clean around the master cylinder reservoir cap. Remove cap and diaphragm carefully. Use a turkey baster to remove most old fluid from the reservoir to minimize contamination.
  2. Refill the reservoir with fresh DOT 3 or DOT 4 fluid to the max level. Do not reuse removed fluid.
  3. Lift ATV so wheels can turn freely where needed. Leave ATV stable on stands with wheels chocked.
  4. Start at the rear caliper. Place clear tubing over the bleeder nipple and submerge the other end in a small container partially filled with fresh fluid to prevent air backflow.
  5. Have an assistant steadily depress the brake pedal/lever several times and hold it down, or use a pressure/vacuum bleeder if available.
  6. Open the bleeder nipple with the wrench about a quarter-turn. Fluid and air will flow into the tubing. Close the nipple before your assistant releases the pedal/lever. Repeat until no air bubbles appear and fluid runs clear.
  7. Watch the master cylinder reservoir level while bleeding. Keep it topped up to avoid drawing air into the system.
  8. Torque the bleeder nipple to factory spec after closing (light snug if spec unknown, then confirm with a torque wrench if possible).
  9. Move to the front right caliper and repeat the same procedure, then complete the front left caliper last.
  10. After bleeding all calipers, sit on the ATV and apply the brake several times to confirm a firm pedal/lever feel. If the lever feels spongy, repeat bleeding sequence focusing on any section that still shows air.
  11. Top up the reservoir to the proper max mark, reinstall diaphragm and cap, and clean any spilled fluid.
  12. Lower the ATV, reconnect battery negative if disconnected, and perform a low-speed test ride to verify braking performance before normal use.

Using a One-Person Bleeder or Vacuum Pump

If using a vacuum pump or commercial one-person bleeder, attach the device to the bleeder nipple, draw fluid and air until clear, and monitor reservoir level. Still follow the same sequence and keep the reservoir topped up.

Torque & Maintenance Values

  • Bleeder nipple: snug to factory spec — if unknown, tighten carefully to avoid stripping; 6-10 Nm is typical for small bleeders but check Suzuki service manual when available.
  • Caliper mounting bolts: inspect and torque to Suzuki spec during reinstallation; verify with service manual or MotoSport technical resources for exact values if removed.

Troubleshooting

  • Persistent spongy feel: check for air in lines, soft hoses, or leaking fittings. Replace any swollen or cracked brake hoses.
  • Brake drag after bleeding: ensure calipers were retracted properly and pistons free; check for overfilled reservoir causing pressure at rest.
  • Leaks: inspect lines, banjo bolts, crush washers, and bleeder nipple seating. Replace crush washers when banjo fittings are disturbed.

Model-Specific Maintenance Tips

  • Master cylinder reservoir is small — maintain careful top-ups during bleeding to prevent introducing air.
  • Use OEM-style crush washers on banjo fittings when servicing brake lines to prevent leaks.
  • Check caliper slide pins and piston seals for corrosion; replace or rebuild calipers if sticking is found, as single-piston calipers rely on smooth piston movement for even braking.
  • Document fluid change date and mileage; change brake fluid every 2 years or sooner if contaminated.

Final Checks

  • Confirm no fluid leaks, firm brake lever/pedal, and even braking on test ride.
  • Clean any spilled brake fluid from painted surfaces with isopropyl alcohol immediately.
  • Properly dispose of used brake fluid according to local regulations.

This MotoSport procedure is tailored for the 2018 Suzuki King Quad 400FSi 4X4 AUTO. For more parts and maintenance items specific to your MMY, use the MotoSport parts link above to find compatible components and recommended supplies.

Related Shopping Categories

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Shop Brake Pads for a 2018 Suzuki King Quad 400FSi 4X4 AUTO ATV.

Shop Brake Lines for a 2018 Suzuki King Quad 400FSi 4X4 AUTO ATV.

Shop Brake Tools for a 2018 Suzuki King Quad 400FSi 4X4 AUTO ATV.

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.