How to Bleed & Replace Brake Fluid on a 2017 Polaris Scrambler 850

Shop parts for a 2017 Polaris Scrambler 850 ATV.

This MotoSport-exclusive step-by-step guide covers safely flushing and bleeding the brake system on a 2017 Polaris Scrambler 850 (MMY: Polaris;SCRAM850;2017). Follow these instructions exactly, use the correct fluid, and observe all safety precautions. If you are not comfortable with brake service, have a qualified technician perform the work.

Why replace brake fluid

Brake fluid absorbs moisture over time, reducing boiling point and increasing corrosion inside lines, master cylinders, calipers and ABS components. Periodic replacement restores performance and longevity of the hydraulic system.

What you need

  • Polaris-recommended brake fluid (DOT 4 unless your owner's manual specifies otherwise). Use fresh, unopened fluid only.
  • Clear tubing that fits the bleeder nipples
  • Brake bleeder bottle or clean catch container
  • Hand vacuum bleeder or a vacuum pump (recommended) or pressure bleeder (optional)
  • Wrenches to fit bleeder nipples (typically 8 mm or 10 mm)
  • Clean rags, latex or nitrile gloves, eye protection
  • Brake cleaner and small funnel with filter screen
  • Jack or ramps and stands to access wheels if needed
  • Plastic sheeting or cardboard to protect finish from spilled fluid

Model-specific notes for the 2017 Scrambler 850

  • The Scrambler 850 commonly has separate master cylinders for front and rear circuits. Treat each circuit independently and identify which master controls which calipers before bleeding.
  • Some model trims may include a hydraulic rear brake connected independently; locate the corresponding master cylinder by tracing the lines. Bleed circuits from the furthest brake from its master cylinder toward the closest.
  • There is no on-board brake fluid reservoir crossover; never mix fluids from different reservoirs.
  • If your Scrambler has an ABS module (less common on base 2017 Scramblers), follow the manufacturer's ABS bleed procedure or use a scan tool to cycle the ABS during bleeding. If unsure, have a dealer perform ABS service.
  • Be careful with paint and plastics — brake fluid damages finish. Cover components under the master cylinder and calipers when working.

Preparation

  1. Park the ATV on level ground, set the parking brake, remove the key and disconnect the battery negative terminal if you will be working near electrical components or ABS unit.
  2. Protect painted surfaces and plastics with cardboard or rags under the master cylinder and calipers.
  3. Clean around the brake fluid reservoir cap(s) with brake cleaner so dirt won't contaminate the system when opened.
  4. Remove reservoir cap(s) and any diaphragm; use a small clean funnel and keep the reservoir topped as you work to prevent air ingress.
  5. Wear gloves and eye protection; brake fluid will irritate skin and damage paint.

Bleed sequence (recommended)

Identify the master cylinder for each circuit. For each circuit, follow the furthest-to-closest wheel sequence relative to that master. Typical sequence examples:

  • If one master controls both front calipers, bleed rear-most front caliper first (usually passenger-side, then driver-side), then the nearest.
  • If a separate rear master exists, bleed the rear circuit starting at the furthest rear caliper first.

Step-by-step bleeding & fluid replacement

  1. Fill the reservoir with fresh DOT 4 fluid and keep it topped during the entire procedure.
  2. Start at the caliper furthest from the master cylinder for the circuit you're servicing. Place clear tubing over the bleeder nipple and route it into your catch bottle partially filled with clean fluid to avoid drawing air back in.
  3. Loosen the bleeder nipple with the correct wrench. If using a vacuum bleeder, attach the hose and apply vacuum. If using the manual pump method, have a helper slowly depress the brake pedal while you open the nipple. If using a pressure bleeder, pressurize the reservoir per tool instructions.
  4. Open the bleeder nipple about a 1/4 turn and allow fluid and air to flow. Close the nipple before the pedal is released (if using a helper) to prevent air from re-entering.
  5. Repeat pump/open/close cycles until clear, bubble-free fluid flows, then tighten the bleeder nipple to spec snug (do not over-torque).
  6. Top up the reservoir as needed between calipers to prevent it from running dry. Running dry will draw air into the system and require restarting the bleed for that circuit.
  7. Proceed to the next caliper in the sequence and repeat until all calipers in that circuit show clear fluid.
  8. After all calipers in the circuit are bled, press and hold the pedal, open the bleeder briefly to ensure no air remains, then close and check pedal firmness. The pedal should be firm and not sink under steady pressure.
  9. Repeat the entire process for the other circuit/master cylinder(s) as required.
  10. Once both circuits are bled and reservoirs are at the correct level, securely reinstall diaphragms and caps. Clean any spilled fluid immediately with water and mild detergent where safe to do so, and use brake cleaner for components.
  11. Reconnect the battery if it was disconnected. Start the ATV and engage brakes at low speed in a safe area to confirm proper braking before riding normally.

Common problems & troubleshooting

  • Spongy pedal after bleeding: likely trapped air; repeat bleeding and ensure reservoir never runs dry.
  • Persistent drop in reservoir level: inspect for leaks at lines, calipers and master cylinder seals; repair before riding.
  • Contaminated fluid (dark, dirty): perform a full flush rather than partial bleed. Use a vacuum or pressure bleeder for a more complete exchange.
  • ABS issues after service: if equipped, an ABS-specific bleed cycle may be required. If ABS warning lights appear, have a dealer read codes and perform the ABS bleed routine.

Disposal & maintenance intervals

  • Dispose of old brake fluid per local hazardous-waste regulations. Do not pour down drains or onto the ground.
  • MotoSport recommends replacing brake fluid every 1-2 years depending on riding conditions or sooner if the fluid is dark or contaminated.

Safety reminders

  • Never mix DOT types (DOT 3, DOT 4, DOT 5) unless explicitly allowed; DOT 5 is silicone-based and incompatible with DOT 3/4 systems.
  • Brake fluid is corrosive to paint and plastics — wipe spills immediately.
  • If you are unsure about ABS-equipped models or the brake system condition, have a certified technician inspect and service your Scrambler 850.

Following this MotoSport proprietary procedure will help restore firm brake feel and maintain the hydraulic system on your 2017 Polaris Scrambler 850. If you need replacement parts, brake fluid or bleeding tools, see the parts page above to find items matched to your MMY.

Related Shopping Categories

Shop Brake Fluid for a 2017 Polaris Scrambler 850 ATV.

Shop Brake Bleeders for a 2017 Polaris Scrambler 850 ATV.

Shop Brake Pads for a 2017 Polaris Scrambler 850 ATV.

Shop Brake Lines for a 2017 Polaris Scrambler 850 ATV.

Shop Brake Tools for a 2017 Polaris Scrambler 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.