Yamaha YZF-R1 Series Service Manual page 778

EAS20695
42_ABS
EAS33324
TROUBLESHOOTING
Item
Rear wheel ABS (intermittent wheel speed pulses or incorrect depressurization)
Procedure
1. Incorrect installation of the rear wheel sensor
• Check the components for looseness, distortion, and bends.
Refer to "MAINTENANCE OF THE REAR WHEEL SENSOR AND SENSOR ROTOR" on page
4-49.
Is check result OK?
YES
→ Go to step 2.
NO
→ Repair or replace the defective part.
2. Incorrect rotation of the rear wheel
• Check that there is no brake disc drag on the wheel and make sure that it rotates smoothly.
Refer to "CHECKING THE REAR WHEEL" on page 4-47 and "CHECKING THE REAR BRAKE
DISC" on page 4-68.
Is check result OK?
YES
→ Go to step 3.
NO
→ Repair or replace the defective part.
3. Rear brake dragging
• Check that the brake fluid pressure is correctly transmitted to the brake caliper when the brake pedal
is operated and that the pressure decreases when the pedal is released.
Refer to "CHECKING THE REAR BRAKE DISC" on page 4-68.
Is check result OK?
YES
→ Go to step 4.
NO
→ Repair or replace the defective part.
4. Defective hydraulic unit assembly
• Replace the hydraulic unit assembly.
Refer to "ABS (Anti-lock Brake System)" on page 4-74.
9-281
42_ABS