How to Bleed and Replace Brake Fluid on a 2015 Suzuki King Quad 400ASi 4X4 AUTO
Shop parts for a 2015 Suzuki King Quad 400ASi 4X4 AUTO ATV.
This MotoSport guide walks you through a complete, workshop-grade brake fluid change and bleed on a 2015 Suzuki King Quad 400ASi 4X4 AUTO. Follow each step carefully, use the recommended brake fluid for your MMY, and always work safely.
What you'll need
- Fresh brake fluid per owner’s manual (use the spec listed in the manual – many Suzuki ATVs accept DOT3 or DOT4; confirm your model)
- Clear plastic tubing that fits bleeder nipples snugly
- Catch bottle for old fluid
- Brake bleeder kit or a hand/vacuum pump (optional but speeds the job)
- Turkey baster or fluid siphon
- Brake cleaner, rags, and disposable gloves
- Wheel chocks, jack and stands (if removing wheels), basic hand tools
- Torque wrench for wheel fasteners and caliper hardware if removed
Safety and prep
- Work on a level surface; chock wheels and ensure the ATV cannot roll.
- Wear eye protection and gloves. Brake fluid is corrosive to paint & plastics; clean spills immediately.
- Do not let old or new fluid contact painted surfaces; rinse with water and cleaners if it does.
- Keep the master cylinder reservoir cap closed except when adding fluid to avoid contamination.
Model notes for the 2015 King Quad 400ASi 4X4 AUTO
- Hydraulic braking system is conventional disc setup with a split circuit master reservoir. Confirm reservoir layout and fluid type in the owner’s manual before starting.
- This MMY typically does not have ABS; procedures here are for standard hydraulic systems. If your ATV has additional brake system electronics, consult a dealer.
- Some 2015 King Quad models use a single combined master cylinder with internal split circuits; bleeding order should prioritize the circuits farthest from the master cylinder first to avoid trapping air.
- If you notice persistent soft pedal or lever after thorough bleeding, inspect calipers, brake hoses, and the master cylinder for internal leaks or degradation common on higher-mileage machines.
Step-by-step: drain, replace fluid, and bleed
1. Inspect and prepare
- Locate the master cylinder reservoir (top of the handlebar area or near the brake pedal). Clean the cap and surrounding area before opening.
- Check and top with fresh fluid only as needed to keep the reservoir from running dry during the procedure.
- Remove wheels only if needed for better caliper access.
2. Remove old fluid from the reservoir
- Use a turkey baster or siphon to remove as much old fluid from the reservoir as possible. Dispose of old fluid properly.
- Refill the reservoir with fresh fluid to the “full” mark. Never mix unknown fluids.
3. Bleeding sequence
Use a logical far-to-near sequence relative to the master cylinder. A common and safe order for a King Quad is:
- Rear right (farthest)
- Rear left
- Front right
- Front left (closest)
If your model's reservoir has clearly separated circuits, bleed each circuit separately following the far-to-near rule within that circuit.
4. Manual bleeding method (pump – partner-assisted)
- Attach clear tubing to the caliper bleeder nipple and place the other end in a catch bottle partially filled with clean brake fluid to avoid drawing air back in.
- Have an assistant slowly depress the brake pedal or lever 3–5 times and hold it down.
- Open the bleeder nipple with a wrench to allow fluid and air to escape until flow slows; close the nipple before the pedal is released.
- Repeat until the expelled fluid is clear and bubble-free, topping the reservoir as needed to prevent it from running dry.
- Move to the next caliper in the sequence and repeat.
5. Vacuum or pressure bleeder method (single-operator)
- Attach your vacuum/pressure bleeder to the caliper bleeder or reservoir per manufacturer instructions. Operate following the same far-to-near sequence, replenishing the reservoir as needed.
- Use caution with pressure bleeders — moderate pressure only to avoid damaging seals.
6. Final checks
- Once all calipers are clear of bubbles and fluid is clear at each bleeder, tighten bleeder nipples to spec snugness. Wipe excess fluid and clean components with brake cleaner.
- Top reservoir to the correct level and replace the cap securely.
- Pump the brake pedal or lever several times with the ATV off to build firm pressure. Inspect for leaks at calipers, hoses, master cylinder, and fittings.
- Lower the ATV and torque wheel fasteners to manufacturer spec if wheels were removed.
Post-service test
- Perform a slow low-speed test in a safe area to verify firm braking and proper behavior. Check pedal/lever feel – it should be firm and consistent.
- If the pedal remains spongy after thorough bleeding, recheck for air, leaking components, or a failing master cylinder.
Maintenance tips & common issues
- Replace brake fluid every 1–2 years or per manual recommendation to avoid moisture buildup and corrosion inside the system.
- Inspect rubber hoses for swelling or cracking on this MMY model; aging hoses can retain air or collapse under pressure.
- Keep a scheduled inspection of caliper slide pins and pads — uneven pad wear can indicate caliper sticking, which compromises bleeding effectiveness.
- Store spare brake fluid sealed and out of direct sunlight; brake fluid absorbs moisture from air rapidly.
If you encounter persistent issues or suspect internal master cylinder damage, contact a MotoSport service specialist or a qualified mechanic experienced with Suzuki ATVs for diagnosis and repair.
Related Shopping Categories
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Shop Brake Tools for a 2015 Suzuki King Quad 400ASi 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.