How to Bleed Polaris Sportsman 850 Brakes

ATV brakes should be bled once a year because brake fluid is hygroscopic, meaning it absorbs water molecules that slowly build up within the fluid and reduce its effectiveness. 

Watch the video above and follow the steps below to bleed the brakes on a Polaris Sportsman 850 

Tools and Supplies - Polaris Sportsman 850XP Brake Bleed

• Ratchet and Torx T20 and T25 bits
• 10mm wrench
• 3/16" x 5/16" clear hose
• Dot 4 brake fluid

PRO TIP: It's possible to bleed the brakes on a Polaris Sportsman without removing the wheels, but doing so makes the job much easier.

Bleeding Polaris Sportsman 850XP Front Brakes

Step 1. Put a 10mm wrench over the bleed screw in the front brake caliper, and attach a length of clear hose from the bleed screw to a container to catch the old brake fluid.

PRO TIP: Always bleed the brake caliper furthest from the brake master cylinder first. For the Polaris Sportsman, this is the right front caliper.

Step 2. Remove the front brake reservoir cover (two Torx T20 screws), then top off the reservoir with Dot 4 brake fluid and replace the cover. 

NOTE: Don't fully retighten the cover screws because you'll have to remove the cover several more times.

Step 3. Pump the front brake lever a couple of times, keep it held in and loosen the caliper bleed screw. Old brake fluid should begin to flow from the caliper into the bleed hose. Tighten the caliper bleed screw.

Step 4. Release and pump the brake lever again before holding the lever and loosening the bleed screw once more. Allow old brake fluid to flow into the bleed hose, and retighten the caliper bleed screw.

Step 5. Keep an eye on the brake fluid level in the reservoir, and pause to refill it whenever necessary.

PRO TIP: Don't let the reservoir run dry, otherwise air will be introduced into the brake lines and you'll have to completely bleed out the system again.

Step 6. Repeat Step 3 and Step 4 until the new brake fluid begins to flow from the brake caliper and there are no air bubbles in the fluid. Make sure the bleed screw is fully tightened and reinstall the wheel.

Next, follow Step 1 through Step 6 to bleed the front brake caliper on the other side of the Sportsman. When both front calipers have been bled, top off the front brake reservoir and reinstall the reservoir cover.

Step 6. Repeat Step 3 and Step 4 until the new brake fluid begins to flow from the brake caliper and there are no air bubbles in the fluid. Make sure the bleed screw is fully tightened and reinstall the wheel.

Bleeding Polaris Sportsman 850XP Rear Brakes

Step 1. Remove the front storage box and the central bodywork plastic beneath it (Torx T25 screws) to access the rear brake reservoir. 

NOTE: The rear brake reservoir is the reservoir with the black cover. Don't confuse it with the reservoir  that has the yellow cover, which is for drive fluid.

Step 2. Remove the rear brake reservoir cover and fill the reservoir with Dot 4 brake fluid. You don't need to replace the rear reservoir cover until you've finished bleeding the rear brakes.

Step 3. Put a 10mm wrench over the bleed screw in the rear brake caliper, and attach a length of hose from the bleed screw to a container to catch the old brake fluid.

PRO TIP: Always bleed the brake caliper furthest from the brake master cylinder first. For the Polaris Sportsman, this is the left rear caliper.

Step 4. Pump the rear brake pedal a couple of times, keep it pressed down, and loosen the caliper bleed screw. Let the old brake fluid flow from the caliper and then tighten the caliper bleed screw.

Step 5. Release and pump the brake pedal again, then hold the pedal, loosen the bleed screw, let out the old brake fluid, and tighten the caliper bleed screw once more.

Step 6. Keep an eye on the brake fluid level in the reservoir, and pause to refill it whenever necessary.

Step 7. Repeat Step 4 and Step 5 until new brake fluid flows from the brake caliper and there are no air bubbles. Make sure the bleed screw is fully tightened and reinstall the wheel.

Step 8. Follow Step 2 through Step 7 to bleed the rear brake caliper on the other side of the Sportsman. When both rear calipers have been bled, top off the rear brake reservoir, then reinstall the reservoir cover, the bodywork and front storage box and you're done.