KTM - DUKE 250

ABS / anti lock brake system (for vehicles with ABS)

The ABS unit 1, which consists of a hydraulic, ABS control unit & return pump is installed under the seat. A wheel speed sensor 2 is located at the front & rear wheel.
The ABS is a safety system that prevents locking of the wheels when the vehicle is traveling straight ahead without the action of lateral forces.

The ABS in 250 Duke two independent brake circuit (front & rear brakes) called as Dual Channel ABS. During normal operation, the brake system operates like a conventional brake system without ABS. When the ABS control unit detects the tendency of a wheel to lock, the ABS begins regulating the braking pressure. The regulating process causes a slight pulsing of the hand brake lever. This pulsing is normal and not defect.

The ABS warning lamp 3 must light up briefly after ignition is switched ON and should then go out after starting off. If it does not go out after starting off or if it lights up while riding, this indicates a fault in the ABS system. The brake system itself stay functional; only ABS control is not available. The ABS warning lamp may also light up if the rotating speeds of the front & rear wheels differ greatly under extreme riding conditions, for example when wheelies or if the rear wheel spins. This causes the ABS to switch off.

To reenable when the vehicle is switched on again. The ABS warning lamp goes out when you start off. Button 4 can be used to switch ABS off manually

Warning Danger of accidents functional limitation of ABS.
- The rear wheel may only be spun with the front brake applied (born out) if the ABS is switched off.
- If the vehicle has been modified, such as shortened or lengthened spring deflection, different rim diameter, different tires, the wrong tire air pressure, different brake linings, etc., the ABS will not functioning optimally. Optimal functioning of the ABS is only ensure if the brake system only contains spare parts and tires that have been approved and / or recommended by KTM.
- Service work and repairs must be performed properly. (Your authorized KTM workshop will be glad to help).

Warning Danger of accidents Rolling over the vehicle.
- It is not always possible to prevent rolling over the vehicle in extreme riding situation (e.g. luggage loaded with a high center of gravity, varying road surfaces, steep descent, full braking disengaging the gear). Adapt your riding style to the road conditions & your riding ability.

Checking the brake discs

Warning Danger of accidents Reduced braking efficiency due to worn brakes disc(s).
- Change the worn brake disc(s) without delay. (Your authorized KTM workshop will be glad to help).

- Check the thickness of the front and rear brake discs at several places on the disk to see if it conforms to measurement A.
If the brake disc thickness is less than the specified value.
- Change the brake discs.
Check front & rear brake discs for damage, cracking, & deformation.
If brake disc shows signs of damage, cracking or deformation - Change the brake discs.

Info
Wear reduces the thickness of the brake disc in area 1 of the brake discs.

Brake discs - wear limit
Front	3.6 mm
Rear	3.5 mm

Note
Danger of accidents Reduced braking efficiency caused by damaged brake discs.

- If the brake linings are not changed in time, the steel brake lining carries grind on the brake disc. The braking effect is greatly reduced and the brake discs are rendered unserviceable. Check the brake linings regularly

Checking the brake fluid level of the front brake

Warning Danger of accidents Failure of the brake system.
- If the brake fluid level falls below the MIN mark, this indicates the leakage in the brake system or worn-out brake linings. Check the brake system and do not continue riding. (Your authorized KTM workshop will be glad to help).

Warning Danger of accidents Reduced braking effect caused by old brake fluid.
- Change the brake fluid of the front and rear brake according to the service schedule. (Your authorized KTM workshop will be glad to help).

- Move the brake fluid reservoir mounted on the handlebar to a horizontal position.
- Check the brake fluid level in viewer 1.
- If the brake fluid is below the MIN marking.
- Add front brake fluid.

Adding front brake fluid

Warning Skin Irritation Brake fluid can cause skin irritation on contact.
- Avoid contact with skin and eyes, and keep out of the reach of children.
- Wear suitable protective clothing and goggles.
- If brake fluid comes into contact with the eyes, flush the eyes thoroughly with water and consult a physician immediately.

Warning Danger of accidents Reduced braking effect caused by old brake fluid.
- Change the brake fluid of the front brake according to the service schedule. (Your authorized KTM workshop will be glad to help).

Warning Environmental hazard Hazardous substances cause environmental damage.
- Oil, grease, filters, fuel, cleaners, brake fluid, etc., should be disposed of as stipulated in applicable regulations.

Info
Avoid contact between brake fluid and painted parts. Brake fluid attacks paint! Use only clean brake fluid from a sealed container.

- Move the brake fluid reservoir mounted on the handlebar to a horizontal position.
- Remove screws 1
- Remove cover 1 with membrane 2.
- Add brake fluid to level A.
- Position the cover with the membrane. Mount and tighten the screws.

Level A	5 mm
Brake fluid DOT 4 / DOT 5.1

Info
Clean up overflowed or spilt brake fluid immediately with water.
Checking the front brake linings

Warning Danger of accidents Reduced braking efficiency caused by worn brake linings.
- Change worn brake linings immediately

Note
Danger of accidents Reduced braking efficiency caused by damaged brake discs.
- If the brake linings are not changed in time, the steel brake lining carries grind on the brake disc. The braking effect is greatly reduced and the brake discs are rendered unserviceable. Check the brake linings regularly.

- Check the brake linings for minimum thickness A. Minimum thickness > 1 mm If the minimum thickness is less than specified
- Change the rear brake linings.Check the brake linings for damage and cracking.
- If there is wear or tearing.
- Change the rear brake linings.

Checking the rear brake fluid level

Warning Danger of accidents Failure of the brake system.
- If the brake fluid level falls below the MIN mark, this indicates a leakage in the brake system or worn-out brake linings. Check the brake system and do not continue riding. (Your authorized KTM workshop will be glad to help).

Warning Danger of accidents Reduced braking effect caused by old brake fluid.
- Change the brake fluid of the front and rear brake according to the service schedule.

- Stand the vehicle upright.
- Check the brake fluid level in the brake fluid reservoir.
If the fluid level reaches the MIN mark 1.
- Add rear brake fluid.

Adding the rear brake fluid

Warning Skin irritation Brake fluid can cause skin irritation on contact.
- Avoid contact with skin and eyes, and keep out of the reach of children.
- Wear suitable protective clothing and goggles.
- If brake fluid comes into contact with the eyes, flush the eyes thoroughly with water and consult a physician immediately.

Warning Danger of accidents Reduced braking effect caused by old brake fluid.
- Change the brake fluid of the front and rear brake according to the service schedule.

Info
Avoid contact between brake fluid and painted parts. Brake fluid attacks paint! Use only clean brake fluid from a sealed container.

- Stand the vehicle upright.
- Remove screw cap 1 with membrane 2.
- Remove cover 2 with membrane 3.
- Add brake fluid to level A.
- Brake fluid DOT 4 / DOT 5.1
- Refit screw cap with membrane.
- info
- Never use DOT 5 brake fluid. It is silicone-based and purple in color. Oil seals and brake lines are not designed for DOT 5 brake fluid.

Info
Clean up overflowed or spilt brake fluid immediately with water.
Checking the free travel of foot brake lever.

Warnings
Danger of accidents Brake system failure.
If there is no free travel on the foot brake lever, pressure builds up on the rear brake circuit. The rear brake can fail due to overheating. Adjust free travel on foot brake lever according to specifications..

- Disconnect spring 1.
- Move the foot brake lever back and forth between the end stop and the contact to the foot brake cylinder - piston and check free travel A.
- If the free travel does not meet specifications.
- Adjust the free travel of the foot brake lever.

Guideline
Free travel at foot brake lever	3.. 5 mm

Info
The range of adjustment is limited.

Checking the rear brake linings

Warnings
Danger of accidents
Reduced braking efficiency caused by worn brake linings.
- Change worn brake linings immediately. (Your authorized KTM workshop will be glad to help).

Note
Danger of accidents
Reduced braking efficiency caused by damaged brake discs.
- If the brake linings are not changed in time, the steel brake lining carries grind on the brake disc. The braking effect is greatly reduced and the brake discs are rendered unserviceable. Check the brake linings regularly.

- Check the brake linings for minimum thickness A. Minimum thickness ≥ 1 mm. If the minimum thickness is less than specified.
- Change the rear brake linings.Check the brake linings for damage and cracking.
- If there is wear or tearing.
- Change the rear brake linings.

Info
Do not pull the hand brake lever when the front wheel is removed.

Warnings
Danger of accidents
Reduced braking due to oil or grease on the brake discs.
- Always keep the brake disc free of oil, grease and clean them with brake cleaner.

Brakes