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

Shop parts for a 2018 Polaris Sportsman 570 ATV.

This MotoSport guide walks you through replacing and bleeding brake fluid on a 2018 Polaris Sportsman 570. Procedures are written for the common non-ABS and ABS-equipped Sportsman 570 variants; when in doubt consult a Polaris dealer before working on ABS components.

Safety & prep

  • Work on a flat, stable surface. Chock wheels and disconnect the battery negative if you will be working near electrical components or ABS modules.
  • Use safety glasses and gloves. Brake fluid can damage paint & plastics — protect surfaces and immediately wipe spills with water.
  • Use only DOT 4 brake fluid unless Polaris documentation for your exact submodel specifies otherwise. Do not mix fluid types.
  • Have a fire extinguisher nearby and dispose of old fluid per local hazardous-waste regulations.

Tools & supplies

  • DOT 4 brake fluid (new, unopened container)
  • Clear vinyl tubing that fits snugly over bleed nipples
  • Small catch bottle with some clean fluid in it to prevent sucking air
  • Wrenches for bleed nipples (typically 8 mm or 10 mm; verify on your calipers)
  • Phillips/flat screwdriver to open reservoir caps, clean rags, gloves, safety glasses
  • Brake bleeder pump or a helper for manual pedal squeezing
  • Torque wrench for caliper mounting hardware if you remove calipers

Understand the brake circuits

The 2018 Sportsman 570 has separate front and rear master circuits. Bleed and flush each circuit independently. If your machine is ABS-equipped, the ABS modulator is installed in-line; basic bleeding will work but if you suspect internal ABS air or failure, have the ABS system serviced by a qualified shop.

Preparation steps

  1. Clean around each brake reservoir cap to prevent contamination.
  2. Remove caps and diaphragms from reservoirs. Keep them level and refill frequently to prevent air entry.
  3. If reservoirs are low, top up with fresh DOT 4 before starting bleed.

Bleeding procedure — manual (helper) method

Perform one circuit at a time. Treat the circuit with the master cylinder you plan to service first.

  1. Start with the caliper furthest from the master cylinder and work to the nearest. For front circuit this is usually the right-front then left-front; for rear circuit check layout and do the furthest first.
  2. Fit clear tubing over bleed nipple and place other end in catch bottle partly filled with fresh fluid so tubing end remains submerged.
  3. Have your helper slowly depress the brake lever/pedal and hold it down. Loosen the bleed nipple about a half turn to allow fluid and air to escape. Tighten nipple before your helper releases the lever/pedal. Repeat until clear, bubble-free fluid flows and no air bubbles appear in the tubing.
  4. Maintain reservoir level between minimum and maximum during the entire process so no new air is drawn into the system.
  5. Work through all calipers in the proper sequence, then perform a final pass of all calipers to confirm no air remains.
  6. Once bleeding is complete, tighten bleed nipples to the correct snugness. Do not overtighten; snug plus a small fraction is appropriate. Wipe all fittings clean.

Bleeding procedure — one-person pump or pressure bleeder

Using a hand-held pump or a pressure bleeder speeds the job and reduces chance of air ingress.

  1. Connect the pressure bleeder to the reservoir cap per tool instructions and pressurize to the tool manufacturer’s recommended setting.
  2. Open the caliper bleed nipple and allow fluid to flow until clear and bubble-free, then close nipple.
  3. Work calipers from furthest to nearest relative to that circuit’s master cylinder.
  4. Depressurize and remove the tool, reseal reservoir cap, and check pedal/lever firmness.

Tips for ABS-equipped Sportsman 570

  • If your 570 has ABS, cycle the ignition per Polaris guidance after bleeding to allow the ABS module to self-check. If bleed feels spongy after fresh fluid, consult a dealer; ABS modulators can trap air and may require special procedures or factory scan tools.
  • Do not power-shop the ABS module or attempt to disassemble it unless trained; fluid contamination can permanently damage electronic components.

Final checks

  • Confirm reservoir caps and diaphragms are clean and properly seated. Tighten caps securely.
  • Test lever/pedal feel — it should be firm with no sponginess. If not, repeat bleeding.
  • Inspect for leaks at calipers, hoses, and fittings after a short test ride at low speed.
  • Torque caliper bolts to factory specs if you removed calipers for any reason; if unknown, tighten to secure and consult service manual for exact values before high-speed use.

Model-specific notes for 2018 Polaris Sportsman 570 owners

  • Polaris typically specifies DOT 4 fluid for the Sportsman 570. Use a fresh sealed container and avoid contamination.
  • The Sportsman 570 often has separate front and rear circuits — do not assume a single master cylinder for both. Bleed both circuits independently.
  • Some 2018 models were offered with optional ABS or advanced brake options. If your ride has ABS, bleeding can be more complex; note ABS warning lights after service and consult a dealer if lights persist.
  • Polaris rubber brake lines can age or crack on high-mileage machines; inspect hoses and fittings while you bleed and replace any suspect components.
  • If you see foam in the reservoir or persistent soft pedal after multiple bleed attempts, the master cylinder may need rebuild/replacement.

Maintenance interval recommendation

For reliable performance, replace brake fluid every 1-2 years or per your service schedule, sooner if fluid is dark, contaminated, or if the bike has been used heavily in wet or muddy conditions. Fresh fluid maintains boiling point and braking consistency.

When to seek professional service

  • If the brake feel remains soft after repeated proper bleeding.
  • If you find internal ABS faults or persistent warning lights.
  • If you are uncomfortable performing the procedure or lack correct tools.

Follow these steps to safely replace and bleed brake fluid on your 2018 Polaris Sportsman 570 and keep braking performance consistent and reliable. For model-specific parts and replacement components, MotoSport has what you need to keep your ride maintained and ready.

Related Shopping Categories

Shop Brake Fluid for a 2018 Polaris Sportsman 570 ATV.

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Shop Brake Pads for a 2018 Polaris Sportsman 570 ATV.

Shop Brake Lines for a 2018 Polaris Sportsman 570 ATV.

Shop Brake Tools for a 2018 Polaris Sportsman 570 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.