How to Bleed & Replace Brake Fluid on a 2006 Polaris Sportsman 800 EFI 4X4

Shop parts for a 2006 Polaris Sportsman 800 EFI 4X4 ATV.

This MotoSport-branded service guide walks you through safely draining, flushing, and bleeding the hydraulic brakes on a 2006 Polaris Sportsman 800 EFI 4X4. Follow these steps precisely, use the recommended materials, and perform a careful test ride before trail use.

What you need

  • DOT 4 brake fluid (Polaris-spec compatible)
  • Clear vinyl hose & catch bottle (for gravity or manual bleeder)
  • Handheld vacuum or pressure bleeder (optional but recommended)
  • Wrenches for bleed nipples and banjo bolts (typically 8mm-10mm)
  • Clean rags, rubber gloves, safety glasses
  • Torque wrench (for banjo bolt reinstallation)
  • Brake cleaner and a small brush
  • Jack or ramps and blocks to safely support the ATV

Model notes — what owners of the 2006 Sportsman 800 should know

  • The Sportsman 800 uses DOT 4 compatible hydraulic fluid; do not mix DOT 5 silicone fluid.
  • Brake master cylinder reservoir location varies by model year/configuration; identify front (handlebar) and rear (foot) reservoirs before starting.
  • Brake lines and fittings on this model can be 10mm banjo bolts with copper crush washers. Always replace crush washers if disturbed.
  • The 800 often has linked braking: a front lever and foot pedal may actuate separate circuits. Know which calipers are served by each reservoir so you bleed the correct circuit sequence.
  • Avoid getting any brake fluid on painted or plastic surfaces — it damages finish. Have cleaner and rags ready.

Safety first

  • Work on a cold engine, stable surface, ignition off, and key removed.
  • Wear eye protection and gloves. Brake fluid is corrosive to paint and harmful to skin.
  • Support the ATV securely with jack stands or ramps; never rely solely on a jack.

Overview of the procedure

You will: 1) identify reservoirs/circuits, 2) remove old fluid from reservoir, 3) flush lines with fresh DOT 4 fluid, and 4) bleed each caliper until clear fluid and no air remain. Use either manual pump-bleeding, vacuum bleed at the caliper, or a pressure bleeder at the reservoir. Reverse (bottom-up) bleeding is effective if air is persistent.

Step-by-step bleed & replace

  1. Locate reservoirs: identify which reservoir feeds which calipers (front/rear or linked). Cap the reservoirs until ready to avoid contamination.
  2. Clean around reservoir caps and bleed nipples thoroughly to keep dirt out.
  3. Remove old fluid from the reservoir(s) using a turkey baster or syringe until level is low but not dry. Inspect fluid color — dark/brown indicates contamination and that a full flush is needed.
  4. Top the reservoir(s) with fresh DOT 4 fluid. Keep the cap loosely on to prevent debris while allowing pressure equalization.
  5. Determine bleed order: start with the caliper farthest from the reservoir and progress to the nearest. On many Sportsman setups that means: far rear, near rear, far front, near front. If brakes are linked, bleed the circuit connected to that reservoir completely before switching.
  6. Attach clear vinyl hose to the caliper bleed nipple; submerge the other end in a bottle partially filled with clean brake fluid to prevent air reentry.
  7. Open the bleed nipple about a quarter turn. Have a helper slowly apply the brake lever or pedal several times and hold it depressed. While held, open the nipple to let fluid & air escape, then close the nipple, then release the lever. Repeat until only clear fluid (no bubbles) flows. Keep reservoir topped up between cycles.
  8. If working alone, use a handheld vacuum pump at the bleed nipple or a pressure bleeder on the reservoir. Vacuum bleed: apply steady vacuum at the nipple and cycle the lever/pedal until clear fluid appears. Pressure bleeder: pressurize reservoir per tool instructions and open bleed nipples in order until clear fluid exits.
  9. For stubborn trapped air, perform reverse bleeding: attach hose to the reservoir (or a reverse-bleed adapter at the caliper) and force fluid from the caliper up to the reservoir, then finish with normal bleed order.
  10. Once clear, snug bleed nipples, wipe clean, and repeat for all calipers/circuits. Replace any crush washers removed during the job and torque banjo bolts to Polaris specifications if available; if not available, tighten snugly and avoid over-torquing.
  11. Top reservoirs to the proper level, secure caps, and clean all spilled fluid. Operate the lever/pedal firmly several times to verify a firm, consistent feel.
  12. Road/test carefully at low speed in a safe area to confirm braking performance. Recheck reservoir levels and bleed nipples after the test ride for leaks or settling air.

Tips & troubleshooting

  • If brake lever or pedal feels spongy after bleeding, re-bleed the circuit and use reverse bleeding if necessary.
  • Always replace copper crush washers on banjo fittings after disconnecting; reused washers often leak.
  • If fluid darkens quickly after bleeding, inspect calipers and lines for contamination or internal seal failure.
  • Store brake fluid sealed and use fresh fluid only; DOT 4 absorbs moisture over time which reduces boiling point.
  • Dispose of used brake fluid responsibly at a recycling facility; do not pour down drains.

When to call a professional

  • If you cannot achieve firm braking after multiple bleed attempts.
  • If you find internal leaks, damaged hoses, corroded lines, collapsed caliper pistons, or master cylinder problems.
  • If you are unsure which reservoir serves which caliper on your specific configuration.

Performing a full brake fluid replacement and bleed on your 2006 Polaris Sportsman 800 EFI 4X4 will restore reliable stopping power when done methodically. If you need OEM replacement parts, seals, or specialized tools, MotoSport carries parts and accessories tailored to this model.

Related Shopping Categories

Shop Brake Fluid for a 2006 Polaris Sportsman 800 EFI 4X4 ATV.

Shop Brake Bleeders for a 2006 Polaris Sportsman 800 EFI 4X4 ATV.

Shop Brake Pads for a 2006 Polaris Sportsman 800 EFI 4X4 ATV.

Shop Brake Lines for a 2006 Polaris Sportsman 800 EFI 4X4 ATV.

Shop Brake Tools for a 2006 Polaris Sportsman 800 EFI 4X4 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.