How to Bleed & Replace Brake Fluid on a 2018 Polaris Sportsman Touring 570

Shop parts for a 2018 Polaris SPORTST570 ATV.

This MotoSport-exclusive guide walks you through safely flushing and replacing the brake fluid on a 2018 Polaris Sportsman Touring 570 (MMY Polaris;SPORTST570;2018). It covers prep, the recommended fluid, step-by-step bleeding procedures, useful checks for the MMY variant, and disposal tips so you can maintain reliable stopping power.

What you need

  • Clean DOT 4 brake fluid (Polaris recommends DOT 4; do not mix with DOT 5 silicone)
  • Brake bleeding kit or clear tubing and a collection bottle
  • Hand vacuum bleeder or 8mm/10mm wrench for bleed screws (confirm screw size visually)
  • Clean rags, isopropyl alcohol for cleaning, gloves and eye protection
  • Floor jack or ATV lift and stands, torque wrench (for wheel removal if needed)
  • Small syringe or turkey baster to remove reservoir fluid

Safety & model-specific notes

  • Work on a flat, stable surface with the engine off and key removed.
  • The Sportsman Touring 570 uses a hydraulic brake system with a handlebar master cylinder for the front and a foot-operated rear master cylinder depending on trim. Confirm which reservoirs your unit has before starting.
  • Some Touring models have linked braking; bleeding both circuits is required. If your machine has any electronic brake modules or ABS, consult Polaris service documentation before attempting bleeding — improper procedures can introduce air into anti-lock components.
  • Never let the reservoir run dry during bleeding; always top with fresh DOT 4 to avoid introducing air.
  • Brake fluid is corrosive to paint and plastics — immediately clean spills with isopropyl alcohol.

Prep

  1. Raise the ATV so wheels are off the ground and secure with stands. Remove wheels if it improves access to caliper bleed screws.
  2. Clean around the master cylinder reservoir caps and caliper bleed screws before opening to prevent contamination.
  3. Remove the reservoir caps and diaphragm, then use a syringe or turkey baster to suck out as much old fluid as possible from each reservoir.
  4. Fill the reservoirs with fresh DOT 4 fluid to the fill mark. Leave the caps loosely on to minimize contamination while still allowing pressure relief.

Bleeding order & method

Bleed the brake furthest from each master cylinder first — this reduces the chance of pushing air back into already bled calipers. Typical recommended order for linked ATV systems is:

  • Rear caliper furthest from master cylinder (usually rear passenger-side)
  • Rear caliper nearest master cylinder (rear driver-side)
  • Front caliper furthest from the front master (usually front passenger-side)
  • Front caliper nearest front master

Two common bleeding methods work well on the Sportsman Touring 570:

1) Manual pump & hold (helper method)

  1. Attach clear tubing to the caliper bleed screw and submerge the tube end in a bottle partially filled with old fluid.
  2. Have a helper pump the brake lever/pedal several times and hold pressure.
  3. Open the bleed screw about 1/4 turn until fluid (and air) flows into the tube, then close the screw before the helper releases pressure.
  4. Repeat until fluid flowing is clear and bubble-free, keeping the reservoir topped with DOT 4 at all times.

2) Vacuum/pressure bleeder (single tech)

  1. Attach your vacuum bleeder to the bleed screw or connect a pressure bleeder to the master cylinder reservoir (follow the tool manufacturer instructions).
  2. Open the bleed screw and operate the bleeder until clear, bubble-free fluid flows.
  3. Close the bleed screw while maintaining flow or vacuum to prevent air re-entry.

Bleed screw handling & finishing

  • Use the correct wrench size and avoid rounding the screw head. Clean screw area after each opening.
  • When each caliper is clear, tighten the bleed screw snugly. If you have torque specs from Polaris, use factory torque; otherwise tighten to a firm seat without over-torquing.
  • Cycle the brake lever/pedal and confirm firm, consistent pressure. If spongy, repeat bleeding sequence.
  • Top reservoirs to the proper level and reinstall diaphragms and caps. Clean any spilled fluid.
  • Reinstall wheels, torque lug nuts to Polaris spec, lower the ATV, and perform a low-speed brake test in a safe area before riding normally.

Inspection & maintenance tips specific to the MMY Sportsman Touring 570

  • Inspect brake lines around the frame and front suspension for nicks, chafing or swelling common on older rubber lines; replace any damaged hoses with OEM or quality braided replacements.
  • Check caliper pistons for free movement and pad wear — touring models carry extra load and tend to wear pads faster if used with heavy cargo or towing.
  • If you find contamination inside the master cylinder or reservoir (rust-colored or dark sludge), a full system flush is critical and consider rebuilding or replacing the master cylinder.
  • If the machine has the factory parking brake or linked system, ensure the parking brake mechanism operates and is released during bleeding to avoid trapped air pockets.

Disposal

Collect old brake fluid and dispose of it as hazardous waste per local regulations. Do not pour down drains or on the ground.

Final checks

  • Confirm zero leaks at bleed screws, lines, and fittings.
  • Verify brake lever/pedal feels firm at normal travel and that stopping distances return to expected levels during a controlled test ride.
  • Document the service date and brake fluid type used for future maintenance.

Follow these MotoSport-tested steps and your 2018 Polaris Sportsman Touring 570 will have a fresh, reliable brake system. If you’re unsure about ABS components, torque specs, or see corrosion inside hydraulic parts, consult a certified Polaris technician.

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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.