How to Bleed & Replace Brake Fluid on a 2019 Suzuki King Quad 400ASi 4X4 AUTO

Shop parts for a 2019 Suzuki King Quad 400ASi 4X4 AUTO ATV.

This MotoSport-exclusive service guide walks you step-by-step through flushing and bleeding the hydraulic brake system on a 2019 Suzuki King Quad 400ASi 4X4 AUTO (MMY code KINGQD4ASI). Follow these instructions carefully, use appropriate safety gear, and consult your owner's manual for any model-specific cautions.

What you need

  • DOT brake fluid: use the specification stamped on your brake fluid reservoir cap (DOT 4 recommended if unspecified by aftermarket sources). Never mix DOT types.
  • Clear plastic tubing that fits snugly over bleeder nipples
  • Brake fluid catch container (marked for hazardous fluids)
  • Hand or vacuum brake bleeder; alternatively a pressure bleeder or two-person helper
  • Ratchet, metric sockets, and wrench set (open-end for bleeder nipples)
  • Brake cleaner, shop rags, and a small brush
  • Latex or nitrile gloves and eye protection
  • Jack and stands or ramps to raise the ATV safely

Model-specific notes for the 2019 King Quad 400ASi 4X4 AUTO

  • The machine uses a conventional hydraulic brake system with separate master cylinder reservoirs for front and rear circuits. Confirm reservoir locations and markings before starting.
  • This model does not have wheel ABS. Bleed and inspect each caliper and the master cylinder for leaks, corrosion, or pitted pistons when servicing.
  • Reservoir caps are plastic with a rubber diaphragm – clean the cap area before opening to prevent contamination.
  • Brake lines on this ATV are routed near frame and steering components; avoid kinking lines while lifting wheels or turning handlebars.
  • If you detect spongy lever/pedal feel after bleeding, bench-bleed the master cylinder or repeat the bleed sequence; trapped air tends to collect at the highest points of the circuit.

Preparation

  • PARK on level ground, engage park/parking brake, and disconnect the battery negative terminal for safety when working near electricals.
  • Raise the ATV safely so wheels can turn, if necessary, and remove any plastic panels that block reservoir or bleeder access.
  • Clean around both reservoir caps and caliper bleeders with brake cleaner to avoid contamination.
  • Fill master reservoir(s) with fresh DOT fluid to the max mark. Keep the cap loosely in place to minimize contamination while still allowing venting during bleeding.

Bleed sequence and method

MotoSport recommends bleeding from the farthest caliper from the master cylinder first, progressing to the nearest. For a typical King Quad layout that means:

  • Rear caliper (if single rear caliper) or rear right then rear left if dual
  • Front calipers: usually right then left (farthest to nearest from master)

Choose one method below. Use the same method for both circuits and keep reservoir level topped up throughout.

Two-person manual bleed

  1. One person pumps the brake lever/pedal slowly to build pressure and then holds it.
  2. Second person opens the bleeder nipple ~1/4 turn until fluid runs into the tubing, then closes the nipple before lever/pedal is released.
  3. Repeat until clear, bubble-free fluid flows and lever/pedal feel is firm.
  4. Move to the next caliper following the sequence above.

One-person vacuum or pressure bleed (preferred for cleanliness)

  1. Attach clear tubing to the bleeder and route it into the catch bottle. Apply vacuum at the bleeder or pressurize the reservoir per tool instructions.
  2. Open bleeder nipple and let fluid and air be drawn out until clear fluid + no bubbles appear.
  3. Tighten bleeder, confirm reservoir level, and move to next caliper.

Master cylinder bench-bleed (when required)

  • If the master cylinder was opened, replaced, or you suspect trapped air near the master, bench-bleed it before final installation. Use small tubing loops into the reservoir and slowly depress the lever until no bubbles appear.
  • Reinstall and perform the full system bleed after bench-bleeding.

Bleeder nipple handling & torque

  • Use the correct wrench to avoid rounding off nipples. With clean fittings, tighten bleeder nipples snugly but avoid over-torquing; these are small fittings and are typically tightened hand-plus-1/4 to 1/2 turn. If you suspect damage, replace the nipple.
  • Inspect banjo fittings for crush washers and replace them if disturbed during service.

Final checks

  • Top reservoirs to the specified level and secure caps with clean diaphragms in place.
  • Operate the brake lever and pedal multiple times to confirm firm response. If soft or spongy, repeat bleeding.
  • Inspect for leaks at calipers, hoses, banjo bolts, and master cylinder.
  • Test ride slowly in a safe area to verify braking performance and pedal feel before normal use.
  • Dispose of used brake fluid responsibly; it is hazardous waste.

Common issues & troubleshooting

  • Persistent spongy feel: likely trapped air in high points or master cylinder not bled properly — bench-bleed and repeat sequence.
  • Brake dragging after bleed: check caliper pistons and slide pins for corrosion; clean and lubricate with dedicated brake grease if needed.
  • Contaminated fluid (dark or particulates): perform a full flush of the system and replace hoses if internal deterioration is present.

MotoSport maintenance tips

  • Flush brake fluid every 2 years or sooner if you ride in wet, muddy, or high-use conditions.
  • Keep a brake service kit on hand with spare bleeder nipples, crush washers, and DOT-spec fluid for field maintenance.
  • Record the date and mileage/hours of service in your maintenance log; consistent documentation prevents overlooked service intervals.

Follow these MotoSport-specific procedures and safety practices to keep your 2019 Suzuki King Quad 400ASi 4X4 AUTO braking system reliable and safe. If you encounter damage to calipers, master cylinder, or lines, replace parts rather than attempting a risky repair.

Related Shopping Categories

Shop Brake Fluid for a 2019 Suzuki King Quad 400ASi 4X4 AUTO ATV.

Shop Brake Bleeders for a 2019 Suzuki King Quad 400ASi 4X4 AUTO ATV.

Shop Brake Pads for a 2019 Suzuki King Quad 400ASi 4X4 AUTO ATV.

Shop Brake Lines for a 2019 Suzuki King Quad 400ASi 4X4 AUTO ATV.

Shop Brake Tools for a 2019 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.