How to Bleed & Replace Brake Fluid on a 2020 KTM 500EXCF

Shop parts for a 2020 KTM 500EXCF Dirt Bike.

This MotoSport-exclusive guide covers safe, effective brake-fluid replacement and bleeding on the 2020 KTM 500EXCF. Follow these steps exactly, use recommended fluids & tools, and take basic safety precautions. If you're unsure about any step, stop and consult a professional mechanic.

What you'll need

  • DOT 4 synthetic brake fluid (fresh, sealed bottle)
  • Clear vinyl hose and a catch bottle (or a brake-bleeder bottle kit)
  • 10 mm wrench (bleeder nipple size may vary)
  • Thin flat screwdriver or small pick (to remove reservoir cap diaphragm)
  • Clean rags, isopropyl alcohol for cleanup
  • Latex gloves and eye protection
  • Torque wrench for reservoir and caliper fasteners (recommended)
  • Optional: vacuum/pressure bleeder or one-way bleeder kit for quicker, cleaner bleeding

Safety & prep notes specific to the 2020 KTM 500EXCF

  • DOT fluids are highly corrosive to paint & plastics. Protect bodywork and forks with rags; wipe spills immediately with isopropyl alcohol.
  • The 2020 KTM 500EXCF does not use mineral oil; use DOT-rated brake fluid only. KTM recommends DOT 4 in stock systems; DOT 5 (silicone) is not compatible.
  • The bike's reservoirs are small. Keep the master-cylinder reservoir topped up during bleeding to avoid introducing air into the system.
  • Front and rear systems are independent. Bleed them separately and keep track of which you're working on.
  • Inspect hoses, banjo fittings, and caliper boots while you're working. Replace any cracked hose or leaking fitting before finalizing the job.

Step-by-step: Replace fluid & bleed the brakes

1. Position the bike & access reservoirs

  • Put the bike on a stable stand so the wheels hang free. That prevents false pressure readings and allows lever/pedal travel.
  • Clean the reservoir tops. Remove the reservoir cap screws, then carefully lift the cap and diaphragm to expose fluid. Avoid tilting the cap so the inside of the cap and the rubber diaphragm remain clean.

2. Remove old fluid from reservoirs

  • Use a syringe or fluid pump to extract as much old fluid as possible from each reservoir (front and rear). This reduces contamination when you add new DOT 4.
  • Dispose of old fluid responsibly; do not pour on the ground.

3. Refill with fresh DOT 4

  • Pour fresh DOT 4 into the reservoir to the recommended level (don't overfill). Reinstall the diaphragm & loosely fit the cap so fluid won't spill during bleeding.

4. Bleeding order and general method

  • Common sequence: bleed the front (master lever) first, then the rear. If you have dual front calipers, bleed the caliper farthest from the master first (typically left then right depending on routing). On most KTM dirt bikes there's a single front caliper, so simply bleed front then rear.
  • Use either the pump-and-hold method, gravity/pressure bleeder, or a vacuum bleeder. For one-person pump-and-hold: one person slowly squeezes the lever/pedal while another opens the bleeder nipple briefly to let fluid/air out, then closes it before the lever/pedal is released. Repeat until you see clear fluid with no bubbles.

5. Front brake bleeding (master lever)

  • Fit clear hose over the bleeder nipple on the front caliper; place the other end in a bottle partially filled with old fluid to prevent air reentry.
  • Have an assistant pump the front lever slowly several times and hold at about 70% travel. Crack the bleeder for a second to let fluid out, then retighten before the lever is released. Repeat until fluid runs clear and bubble-free. Keep reservoir topped up throughout.
  • Tighten the bleeder nipple to spec snugness (hand tight + small turn). Clean any spilled fluid and torque fasteners to KTM specs if available.

6. Rear brake bleeding (pedal)

  • Locate rear master cylinder reservoir (usually under helmet compartment or near airbox on EXC-F models) and bleed the caliper in the same manner as front. Pedal bleeding is identical to lever bleeding; pump pedal, hold, open bleeder briefly, close, repeat.
  • Pay attention to pedal return & feel. If the pedal is spongy after bleeding, repeat until firm.

7. Reverse-bled caliper option (if stubborn air)

  • If air is trapped in caliper cavities, reverse bleeding (pushing fluid from caliper up to master) often expels stubborn pockets. Attach hose to the master reservoir and press fluid from caliper up to reservoir using a pressure bleeder or syringe at the caliper while the lever/pedal is actuated appropriately.

8. Final checks

  • Top reservoir(s) to the correct level, reinstall diaphragm & cap, and tighten screws evenly.
  • Operate lever & pedal multiple times to confirm a firm, consistent feel. Check for leaks at bleeder nipples, banjo bolts, and hose fittings.
  • Clean all residual fluid; inspect brake pads & rotor condition. Replace pads if worn or contaminated with fluid.
  • Test-ride gently in a safe area, checking braking performance before normal riding.

Torque & maintenance notes specific to KTM 500EXCF owners

  • Banjo bolt crush washers are single-use; replace crush washers when you disturb a banjo fitting to prevent leaks. Carry spare copper/plastic washers when you work on the brakes.
  • Caliper mounting bolts and banjo bolts should be tightened to KTM-specified torques. If you don't have the exact numbers, tighten progressively & use a torque wrench to factory specs from your service manual.
  • Change brake fluid at least every 1-2 years depending on riding conditions & moisture exposure. Racing or heavy water exposure requires more frequent changes.
  • If your bike has aftermarket master cylinders or lines, follow the manufacturer's fluid recommendations and bleeding procedures; some aftermarket parts require DOT 5.1 or different techniques.

Troubleshooting

  • Persistent sponginess: likely remaining air or contaminated pads/rotor. Re-bleed, inspect pads, and replace if fluid-soaked.
  • Lever/pedal travel suddenly increases after bleeding: check for leaks or a damaged master cylinder seal.
  • Leaky bleeder nipple: tighten or replace nipple; if it still leaks, inspect caliper threads and consider caliper overhaul.

Performing a clean, careful fluid replacement and bleed restores braking performance and safety. Keep a maintenance log for the MotoSport service record & schedule fluid changes seasonally if you ride in wet conditions frequently.

Related Shopping Categories

Shop Brake Fluid for a 2020 KTM 500EXCF Dirt Bike.

Shop Brake Bleeders for a 2020 KTM 500EXCF Dirt Bike.

Shop Brake Pads for a 2020 KTM 500EXCF Dirt Bike.

Shop Brake Lines for a 2020 KTM 500EXCF Dirt Bike.

Shop Brake Tools for a 2020 KTM 500EXCF Dirt Bike.

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.