Upgrading to NUTT full hydraulic brakes delivers substantial performance and safety advantages for high-power KuKirin scooters:

• Superior Braking Power & Shorter Stopping Distance: Hydraulic fluid transfers force without cable stretch, reducing required lever effort by over 50%.
• Dual-Piston Simultaneous Clamping: Unlike single-actuation mechanical calipers that push the rotor from one side, NUTT dual-action pistons clamp evenly from both sides, preventing rotor warping.
• Reduced Hand Fatigue: Smooth, progressive lever feel enables precise 1-finger or 2-finger braking during fast descents or high-speed cruising.
• Integrated Electronic Safety: Built-in motor power-off sensors instantly cut motor throttle the moment the brake lever is pulled.

Depending on whether you choose Front Only, Rear Only, or Front + Rear Set, each kit typically includes:

• Pre-bled CNC-machined brake lever(s) with integrated electronic cut-off switches.
• Dual-piston hydraulic caliper(s) with pre-installed resin-metallic brake pads.
• Reinforced hydraulic oil lines (1350 mm Front / 2200 mm Rear).
• Model-specific mounting brackets, caliper mounting bolts, and required washers/spacers.

Yes. Every NUTT brake system is factory vacuum-filled and pre-bled with high-grade mineral oil. If your scooter frame allows external or split-bracket routing, it can be installed plug-and-play without opening the hydraulic circuit.

Our kits are tailored for the most popular KuKirin / KugooKirin platforms:

• KuKirin G2 Pro: Requires verification of front fork revision and disc offset.
• KuKirin G2 Max: Requires precise clearance check (>2 mm gap between caliper body and motor rim).
• KuKirin G3 / G3 Pro: Fully supported with appropriate mounting adapters.
• KuKirin G4: Compatible; requires keeping original factory washers for alignment.
• KuKirin G1 / M4 / M4 Pro / Master: Compatible with specific rotor side and mount brackets.

Because KuKirin made structural modifications across different production batches of the G2 Pro:

• Check your front fork caliper mount type (A-pillar Post Mount vs. B-pillar IS Mount).
• Some G2 Pro production years require a 5 mm brake rotor spacer on the front wheel hub to prevent the caliper body from rubbing against the motor housing or wheel spokes.

For the KuKirin G2 Max, the rear swingarm and motor casing have tighter tolerances:

Standard kits feature high-pressure braided hydraulic lines in the following lengths:

• Front Line: 1350 mm (1.35 m) — Optimized for tall handlebars and wide steering angles.
• Rear Line: 2200 mm (2.2 m) — Sufficient for routing through long chassis decks and rear swingarms.

If you have basic mechanical experience and hex keys (4mm / 5mm), installation takes approximately 30–60 minutes. However, if your scooter requires internal hose cutting, routing, and bleeding, we recommend having it done by a qualified technician or following our step-by-step video guide carefully.

When installing on the KuKirin G4, do not discard the original factory metal washers. Retain all original conical and flat washers until test-fitting is complete, as they are essential for achieving optimal caliper height and rotor center alignment.

1. Loosen the two caliper mounting bolts slightly so the caliper can slide side-to-side.
2. Squeeze the brake lever firmly 3–4 times, then hold it clamped tightly against the grip.
3. While holding the lever clamped, alternately tighten the two caliper bolts to 6–8 Nm.
4. Release the lever and spin the wheel to verify that the disc rotor spins freely without contact.

NUTT brake levers feature a built-in magnetic Hall-effect / reed sensor. As soon as you initiate lever travel (within 1–2 mm of movement), the internal switch signals the scooter controller to immediately shut off motor power and activate regenerative electronic braking (if supported by your controller).

KuKirin scooters use different connector standards depending on the model and production year:

• 2-Pin Waterproof Julet / Higo Connector (Red/Black): Common on modern G2 Pro, G2 Max, and G4.
• 3-Pin Waterproof Connector (Yellow): Used on specific display-integrated controller models.
• Standard 2-Pin SM / JST White Plugs: Found on older KuKirin M4 / G-Booster wiring harnesses.

Always inspect your scooter's existing brake lever connector before ordering.

Elevate the scooter securely on a stand so the driven wheel is off the ground. Gently engage the throttle to spin the motor at low speed, then lightly pull the brake lever. The motor should disengage instantaneously before the physical pads make full contact with the disc.

NUTT hydraulic brakes use Mineral Oil ONLY.

• Routine Check: Inspect brake fluid level and lever firmness every 500 km or 3 months.
• Full Fluid Flush / Bleed: Recommended every 12–18 months, or whenever the brake lever feels "spongy" or loses immediate stopping bite.

Use only dedicated Isopropyl Alcohol (IPA ≥90%) or residue-free bicycle brake cleaner. Never use WD-40, degreasers with lubricants, soap with wax additives, or petroleum solvents near calipers and rotors.

To achieve maximum braking power and prevent squealing, new pads and rotors must be properly bedded in:

1. Ride the scooter at a moderate speed (approx. 20–25 km/h) in a safe, open area.
2. Apply the brakes firmly and evenly until speed drops to 5 km/h (do not come to a complete stop or lock wheels).
3. Repeat this process 15–20 times. You will feel braking power increase significantly as friction material transfers evenly onto the rotor surface.

Yes. NUTT CNC calipers feature large heat-dissipation surfaces and heat-resistant mineral oil formulas engineered to resist thermal fade during prolonged braking. For heavy riders (>100 kg) or extreme downhill riding, we recommend 140 mm or 160 mm floating rotors for enhanced thermal management.

Yes. The hydraulic system is fully sealed against rain, mud, and dust. Note that wet rotors may produce temporary squeal until water is cleared from the contact surface during the first couple of braking strokes.

Cause: Air micro-bubbles are trapped inside the hydraulic line or lever reservoir.

Solution: Perform a simple bleed procedure using a NUTT mineral oil bleed funnel at the lever bleed port to release trapped air bubbles until the lever feels rock solid.

Common causes and remedies:

• Oil Contamination: Even a tiny droplet of chain lube, road oil, or cleaning wax will glaze pads. Clean the rotor thoroughly with Isopropyl Alcohol and sand the pads lightly with 400-grit sandpaper, or replace contaminated pads.
• Improper Alignment: Ensure the rotor is running parallel and centered between the two pads.
• Incomplete Bed-In: Complete the 20-cycle bed-in procedure.

Brake dust can occasionally cause one piston seal to stick. Remove the pads, hold the active piston in place with a plastic tire lever, gently squeeze the lever to push the sluggish piston out 1–2 mm (do not pop it out completely), clean the piston sides with isopropyl alcohol and mineral oil lubricant, then push both pistons back flush.

We provide a 1-Year Limited Manufacturer Warranty covering:

• Defects in CNC lever and caliper castings.
• Internal master cylinder and caliper seal leakage under normal usage.
• Integrated electronic power-off sensor malfunction.

Note: Normal consumable wear (brake pads, rotor wear), crash damage, improper trimming, or damage caused by using corrosive DOT fluids are excluded from warranty coverage.

Yes. We stock full replacement components on our store including original semi-metallic & ceramic pads, replacement compression olives/barbs, pre-cut oil hoses, and dedicated bleed kits.

Locate the 2 mm or 2.5 mm reach adjustment hex screw on the inside pivot of the brake lever. Turn clockwise to bring the lever blade closer to the grip (for smaller hands), or counter-clockwise to extend the lever blade outward for larger hands.

• Resin / Semi-Metallic (Default): Fast initial bite, silent operation, and gentle on rotors. Ideal for city commuting and standard conditions.
• Full Metallic / Sintered: Maximum heat resistance, longer lifespan, and superior wet-weather stopping power. Ideal for aggressive riding, dual-motor speed runs, and steep hills.
• Ceramic Compound: Exceptional heat dissipation with minimal brake dust and ultra-low noise under high-speed thermal load.

Yes, by using a specialized stealth-trim method:

1. Keep the caliper low and hold the brake lever elevated at the highest position.
2. Carefully cut the hose cleanly with a sharp hydraulic hose cutter at a 90-degree angle.
3. Immediately press in a new brass insert barb and slip on a fresh compression olive.
4. Re-tighten the compression nut to 5–7 Nm into the lever body.
5. Top up 1–2 drops of mineral oil at the lever bleed port to ensure zero air ingress.