How to bleed and replace brake fluid on a 2009 Suzuki King Quad 400AS 4X4 AUTO
Shop parts for a 2009 SUZUKI KINGQD400A ATV.
This MotoSport service guide walks you through safely flushing and bleeding the brake system on a 2009 Suzuki King Quad 400AS 4X4 AUTO. It is written for owners who want a reliable DIY job that restores pedal feel and removes moisture and contamination from the hydraulic system. Follow every safety note, use the correct fluid, and dispose of old fluid responsibly.
What you need
- New DOT brake fluid (use DOT 4 unless your owner’s manual specifies otherwise)
- Clear plastic tubing sized to bleed nipples
- Brake bleed wrench or correct open-end wrench
- Vacuum bleeder or two-person helper (pump-and-hold) or pressure bleeder
- Clean catch container and rags
- Disposable gloves, safety glasses
- Turkey baster or syringe (to remove fluid from master cylinder)
- Torque wrench for re-installing components if removed
Model notes specific to the 2009 King Quad 400AS 4X4 AUTO
- The King Quad 400AS uses a hydraulically actuated brake system with separate calipers/master cylinder reservoirs depending on front/rear configuration – check the master cylinder caps for front and rear reservoirs and service both circuits separately.
- This ATV has rugged use in off-road conditions — mud and water ingress accelerate fluid moisture contamination, so plan to flush every 1-2 years or sooner if brakes feel spongy.
- Brake fluid is hygroscopic; because ATVs see more moisture, prefer DOT 4 for higher boiling point unless Suzuki specifies DOT 3. Confirm the stamped cap or owner's manual before final selection.
- Protect painted plastics and frame: brake fluid damages paint and plastics, so cover surfaces and clean spills immediately.
Preparation
- Park on level ground, apply park brake, and remove key. Secure with wheel chocks if necessary.
- Lift and support the ATV so wheels you will bleed are off the ground if needed. Remove wheels for easier access to bleeder nipples when required.
- Clean around each bleeder screw and master cylinder cap to prevent contamination.
- Open master cylinder reservoir(s) and inspect fluid color. Brown/black fluid indicates replacement.
- Top reservoir to the MAX line with new DOT 4 fluid before starting; do not let reservoir run dry during bleeding.
Bleed sequence and methods
General rule: bleed from the caliper farthest from the master cylinder first, then proceed to the nearest. On most King Quad layouts this means bleeding in this order if applicable: rear passenger side (farthest), rear driver side, front passenger, front driver. If you aren’t sure which is farthest, pick a logical outside-to-inside or rear-to-front progression. Always keep the master cylinder topped up.
Two-person pump-and-hold method
- Attach clear tubing to the bleeder nipple and submerge the other end in a small catch container partially filled with clean fluid to prevent air re-entry.
- Person A pumps the brake lever/pedal several times and holds steady pressure.
- Person B opens the bleeder nipple about 1/4 turn until fluid plus air bubbles flow into the tubing, then close the nipple before the lever/pedal is released.
- Repeat until no bubbles appear and fluid runs clear. Replenish reservoir frequently.
- Move to the next wheel in sequence and repeat.
Vacuum or pressure bleeder method (preferred for single tech)
- Connect vacuum pump to bleeder nipple or pressure bleeder to reservoir per tool instructions.
- Operate tool while opening the bleeder nipple to draw fluid out until clear fluid appears and no bubbles are present.
- Close bleeder while under vacuum and move to next wheel. Keep reservoir topped off.
Bench-bleeding master cylinder (if removed or full replacement)
- Secure master cylinder in a vise or stable fixture and use bench-bleed fittings and tubing to return fluid to the reservoir while you operate the lever/pedal by hand until no bubbles appear.
- Install back on the ATV and then perform wheel bleeding to clear the rest of the system.
Finishing steps
- When all wheels are bled and fluid runs clear with firm pedal/lever feel, tighten bleeder nipples to spec snugness, wipe clean, and top reservoir to MAX line. Do not overfill.
- Reinstall wheels and torque fasteners to factory values. Lower the ATV and perform a controlled brake test at low speed in a safe area to confirm performance.
- Dispose of old brake fluid as hazardous waste according to local regulations.
Troubleshooting & tips
- If pedal remains spongy after bleeding, suspect an internal leak, collapsed brake hose, or a bad master cylinder — inspect lines, fittings, and caliper piston seals.
- Replace rubber hoses older than 5-7 years or any with visible cracking/swelling; flexible hoses can trap air and reduce system integrity.
- Use fresh unopened DOT fluid. Do not mix DOT 5 silicone with DOT 3/4 fluids.
- After riding in deep water, recheck brake fluid and operation; moisture intrusion can reduce boiling point quickly.
MotoSport maintenance recommendation
MotoSport recommends flushing the entire brake system on the King Quad 400AS every 12-24 months depending on use, and immediately if brakes feel soft after heavy use or water exposure. Keep a maintenance log and use OE-equivalent parts when replacing master cylinders, calipers, or hoses.
Related Shopping Categories
Shop Brake Fluid for a 2009 SUZUKI KINGQD400A ATV.
Shop Brake Bleeders for a 2009 SUZUKI KINGQD400A ATV.
Shop Brake Pads for a 2009 SUZUKI KINGQD400A ATV.
Shop Brake Lines for a 2009 SUZUKI KINGQD400A ATV.
Shop Brake Tools for a 2009 SUZUKI KINGQD400A 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.
