How to Add Brake Fluid to the Front and Rear Hydraulic Brakes on an Arwibon Q06Pro

If the brake lever on your Arwibon Q06pro feels soft, pulls unusually close to the handlebar, or has gradually lost its firm hydraulic feel, the brake system may need a small amount of fluid added at the lever reservoir.

This guide follows the brake-oiling procedure for the Arwibon Q06 Pro electric scooter. It covers both the front and rear hydraulic brake levers.

This procedure is intended for a minor fluid top-up. If the brake system contains a significant amount of air, has been opened at the hose or caliper, or remains spongy after topping up, a complete hydraulic brake bleed may be required.

Tools and Materials Needed

• 2.5 mm Allen wrench
• Correct mineral brake fluid for the installed hydraulic brake system
• Fine-tip fluid bottle
• Clean paper towels or shop cloth
• Protective gloves

Do not substitute automotive DOT brake fluid unless the brake manufacturer specifically specifies it. The system shown in this Q06Pro procedure uses mineral-type hydraulic brake fluid.

Step 1: Locate the Front Brake Fill Port

Start at the left side of the handlebar.

The left hydraulic brake lever operates the front brake on the Q06Pro configuration shown in the procedure.

Locate the small Allen screw on top of the brake lever reservoir.

This is the fluid fill port.

Before removing it, place a clean cloth around the lever body so any spilled fluid can be caught immediately.

Step 2: Remove the Front Brake Fill Screw

Insert a 2.5 mm Allen wrench into the small fill screw.

Turn it counterclockwise slowly and remove it.

Pay close attention to the small sealing O-ring fitted to the screw.

Do not lose or damage this seal. If the O-ring is missing, cut, or badly flattened, reinstalling the screw may not seal the reservoir correctly.

Place the screw somewhere clean while you work.

Step 3: Add Fluid to the Front Brake Reservoir

Insert the narrow tip of the mineral-oil bottle into or directly above the fill opening.

Add the fluid slowly.

Do not squeeze the bottle aggressively. Add only enough fluid to bring the level to the opening as shown in the procedure.

Keep the bottle and fill port clean so dirt does not enter the hydraulic system.

Step 4: Gently Operate the Front Brake Lever

After adding fluid, slowly squeeze and release the front brake lever several times.

Use short, controlled lever movements.

This can help small air bubbles near the lever reservoir rise toward the fill opening.

Do not assume this step replaces a full brake bleed. Air trapped farther down the hose or inside the caliper may require proper bleeding equipment and a different service procedure.

Add a small amount of fluid again if the level drops while the lever is being operated.

Step 5: Reinstall the Front Brake Fill Screw

Place the fill screw back into the reservoir by hand first.

Make sure the O-ring remains correctly seated.

Turn the screw a few threads by hand before using the Allen wrench. This reduces the chance of cross-threading the small threaded hole.

Use the 2.5 mm Allen wrench to tighten the screw until the seal is seated securely.

Do not overtighten it. This is a small service screw and does not require excessive force.

Wipe all remaining brake fluid from the lever body.

Step 6: Locate the Rear Brake Fill Port

Move to the right side of the handlebar.

On the Arwibon Q06Pro configuration shown here, the right hydraulic brake lever operates the rear brake.

Locate the same small fill-port screw on top of the rear brake reservoir.

Clean the surrounding area before opening the reservoir.

Step 7: Remove the Rear Brake Fill Screw

Use the 2.5 mm Allen wrench to loosen the screw counterclockwise.

Remove it carefully and check that the small sealing O-ring comes out with the screw.

Keep the screw and seal clean.

Step 8: Add Fluid to the Rear Brake Reservoir

Place the fine-tip bottle at the fill opening and add the correct mineral brake fluid slowly.

Bring the fluid up to the fill-port level without overfilling or spraying fluid around the handlebar.

Then slowly squeeze and release the rear brake lever several times.

Watch the fluid level while doing this.

If small bubbles appear near the opening, allow them to escape before reinstalling the screw.

Step 9: Reinstall the Rear Brake Fill Screw

Return the screw to the fill opening by hand.

Check the O-ring position before tightening.

Thread the screw in carefully, then use the 2.5 mm Allen wrench to seat it securely.

Do not force the screw after the seal has compressed.

Clean all spilled fluid from the brake lever and nearby components.

Step 10: Keep Brake Fluid Away From the Rotor and Pads

During both front and rear brake service, keep mineral oil away from the brake rotors and brake pads.

Oil contamination on the braking surfaces can sharply reduce friction.

If fluid contacts the rotor, clean the rotor thoroughly with a brake-compatible cleaner or suitable isopropyl alcohol before using the scooter.

If the brake pads absorb oil, cleaning may not fully restore their braking performance. Contaminated pads may need to be replaced.

Do not perform a riding test until the braking surfaces are clean and dry.

Step 11: Test the Front Brake Lever

Squeeze the left front brake lever repeatedly.

The lever should build hydraulic resistance and should not simply pull all the way back to the handlebar.

Check for:

• A firmer lever feel
• Smooth lever return
• No visible fluid leakage around the fill screw
• No sudden loss of hydraulic pressure

There is no fixed requirement that the brake must engage at exactly one-third or one-half of the lever travel. Lever travel can vary with brake adjustment, pad wear, caliper setup, and the hydraulic system.

Step 12: Test the Rear Brake Lever

Repeat the same check on the right rear brake lever.

Squeeze and release it several times.

The lever should return normally and maintain consistent hydraulic resistance.

If the lever still feels spongy, slowly moves toward the handlebar while being held, or repeatedly loses pressure, do not assume that adding more fluid will solve the problem.

Inspect the hydraulic system for air, leakage, worn components, or another brake fault.

Step 13: Perform a Stationary Brake Test

Before riding the arwibon q06pro, test both brakes while the scooter is stationary.

Apply the front brake and gently push the scooter.

Repeat the test with the rear brake.

Both brakes should hold the scooter without the lever collapsing toward the grip.

Then inspect the lever reservoirs, hoses, hose fittings, and calipers for any sign of fresh fluid leakage.

If you find a leak, do not ride the scooter until it has been repaired.

When a Fluid Top-Up Is Not Enough

Adding fluid at the brake lever is suitable only for the type of minor service shown in this Q06pro procedure.

A full bleed should be considered if:

• The lever remains spongy after the top-up
• Air continues to appear in the reservoir
• A brake hose has been disconnected
• A hose or fitting has leaked
• The caliper has been opened
• Brake pressure repeatedly disappears
• The lever still reaches the handlebar

A hydraulic brake fault should be repaired before the scooter returns to normal riding.

Arwibon Q06Pro Service and Parts Note

This procedure is written for the arwibon q06 pro and the hydraulic brake configuration shown on the arwibon q06 pro electric scooter. Owners searching for arwibon q06, q06pro, or q06 pro electric scooter service information should always confirm the actual brake model fitted to the scooter before selecting brake fluid or replacement parts.

When buying arwibon scooter parts, match the brake lever, caliper, hose, seals, and fluid type to the installed system. General searches for arwibon scooter, arwibon electric scooter, arwibon scooters, or arwibon e scooter parts may include components for several different models.

The same distinction applies to arwibon scooter charger products. A search such as q06pro electric scooter off road chargers concerns the scooter's charging system and has no connection with the hydraulic brake fluid used in this repair.