How to Bleed & Replace Brake Fluid on a 2020 Polaris Sportsman Touring 850
Shop parts for a 2020 Polaris Sportsman Touring 850 ATV.
Overview & safety
- Work on a flat, stable surface. Chock wheels. Wear nitrile gloves and eye protection.
- Brake fluid is hygroscopic and damages paint & rubber. Keep containers closed and clean up spills immediately with water.
- Use the manufacturer-specified fluid. For the 2020 Polaris Sportsman Touring 850 use DOT 4 brake fluid or the DOT rating specified in your owner’s manual. Never mix DOT 3/4/5.1/5 unless specified.
- If your unit is equipped with ABS or an electronic brake module, consult Polaris dealer instructions before attempting service. Many Touring 850s are non-ABS; if yours has ABS, special procedures or a dealer bleed tool may be required.
Tools & supplies
- DOT 4 brake fluid (fresh, unopened)
- Clear plastic tubing and a catch bottle
- Box wrench or socket for bleed nipples (typically 8mm or 10mm)
- Flat screwdriver for master cylinder cap clips
- Hand pump vacuum bleeder (optional) or pressure bleeder (optional)
- Clean rags, gloves, and safety glasses
- Torque wrench for caliper hardware if removing calipers (refer to Polaris torque specs)
Preparation
- Locate the master cylinder reservoir. On the Sportsman Touring 850 it is under the front rack area or directly forward of the handlebar remove the cover/panels to access it.
- Clean around the reservoir cap to prevent contamination. Remove the cap and diaphragm carefully. Inspect fluid color — dark, cloudy or contaminated fluid needs full replacement.
- Identify bleed nipples on each caliper. Raise the ATV as needed and secure on stands for wheel access.
Bleed sequence
Always start with the caliper farthest from the master cylinder and work toward the nearest. For the Touring 850 that commonly means:
- Rear caliper farthest wheel
- Rear near side
- Front far side
- Front near side
If unsure which is farthest, visually trace the brake lines from the reservoir to each caliper.
Step-by-step bleed & replace (manual method)
- Top off the master cylinder with fresh DOT 4 fluid. Keep the cap loosely installed between steps to minimize air entry.
- Fit clear tubing over the first caliper bleed nipple and submerge the other end in a catch bottle partially filled with fresh fluid to prevent air re-entry.
- Have an assistant slowly depress the brake lever/pedal several times and hold it down. Crack the bleed nipple slightly to let fluid & air escape, then tighten before the assistant releases the lever. Repeat until no air bubbles appear in the tubing and the fluid runs clear.
- Keep the master cylinder fluid level topped up throughout. Never let it drop to empty or you will introduce air into the system.
- Move to the next caliper in the sequence and repeat.
- When complete, tighten all bleed nipples to snug — avoid over-torquing. Clean any spilled fluid and reinstall the reservoir cap with a clean diaphragm and filter screen in place.
- Test brake lever/pedal feel with ATV on the ground. If spongy, repeat bleeding until firm and consistent.
Alternative methods
- Vacuum bleeder: Attach to bleed nipple, draw fluid until clear, maintain reservoir level. Faster for one-person jobs.
- Pressure bleeder: Pressurize reservoir with a dedicated tool to push fluid through system — good for complete flushes, safe and quick.
Full fluid replacement (flush)
- Use the same sequence but continue bleeding until clean, new fluid exits each caliper. This ensures old hygroscopic fluid is removed from all lines and calipers.
- Replace rubber components showing swelling or deterioration (hoses, seals) before refilling if present.
Final checks & notes specific to the 2020 Sportsman Touring 850
- EPS models: Electric power steering does not change hydraulic brake system procedure but avoid contact of fluid with electrical connectors. Disconnect battery when removing major body panels near electronics.
- Parking brake: If your ATV has a manual parking brake cable, bleeding the hydraulic brakes will not affect the mechanical parking brake; inspect and adjust separately.
- Brake line routing: Inspect lines for chafing against racks or frame, especially if aftermarket racks or storage have been added to the Touring model.
- Reservoir access: Some Touring 850 configurations have small access openings under the front rack; remove racks/panels for easier servicing if needed.
- Service interval: Replace brake fluid every 12 to 24 months depending on use and moisture exposure; heavy off-road use or water crossings justify annual replacement.
- If you detect persistent sponginess after several manual attempts, or if the unit is ABS-equipped, have a Polaris dealer perform a diagnostic bleed and inspect the master cylinder and calipers.
Disposal & cleanup
- Dispose of used fluid at an approved hazardous waste or recycling center. Do not pour down drains.
- Rinse skin and painted surfaces with water immediately if fluid contacts them; brake fluid can strip paint.
Troubleshooting
- Continuous soft lever/pedal after bleeding: check for leaks, collapsed hoses, or a failing master cylinder.
- Air returns after apparent successful bleed: likely reservoir ran low during process or a leak is present between reservoir and master cylinder.
Perform a slow, cautious test ride in a safe area after bleeding to confirm brake performance. If in doubt, contact a Polaris-certified technician.
Related Shopping Categories
Shop Brake Fluid for a 2020 Polaris Sportsman Touring 850 ATV.
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Shop Brake Lines for a 2020 Polaris Sportsman Touring 850 ATV.
Shop Brake Tools for a 2020 Polaris Sportsman Touring 850 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.