Yamaha YZF-R125 Service Manual: Checking the front brake master cylinder

Yamaha YZF-R125 Service Manual / Chassis / Front brake / Checking the front brake master cylinder

1. Check:

  • Brake master cylinder Damage/scratches/wear Replace.

  • Brake fluid delivery passages (brake master cylinder body) Obstruction Blow out with
    compressed air.

2. Check:

  • Brake master cylinder reservoir Cracks/damage Replace the brake
    master cylinder.
  • Brake master cylinder reservoir diaphragm Damage/wear Replace.

3. Check:

  • Brake hose Cracks/damage/wear Replace.

Assembling the front brake master cylinder

WARNING
  • Before installation, all internal brake components should be cleaned and lubricated with clean or new brake fluid.
  • Never use solvents on internal brake components.
    Removing the front brake master cylinder
    NOTE: Before removing the front brake master cylinder, drain the brake fluid from the entire brake system. 1. Disconnect: Front brake light switch 2. Remove: Brake hose union bolt Copp ...

    Installing the front brake master cylinder
    1. Install: Brake master cylinder "1" Brake master cylinder holder "2" NOTE: Install the brake master cylinder holder with the arrow mark "a" pointing forward. Align the end of the br ...

    Other materials:

    Checking the crankshaft position sensor
    1. Disconnect: Crankshaft position sensor coupler (from the wire harness) 2. Check: Crankshaft position sensor resistance Out of specification  Replace the crankshaft position sensor/stator assembly. a. Connect the pocket tester ( × 100) to the crankshaft position sensor c ...

    Removing the front wheel (disc)
    1. Stand the vehicle on a level surface. WARNINGSecurely support the vehicle so that there is no danger of it falling over. 2. Elevate: Front wheel NOTE: Place the vehicle on a suitable stand so that the front wheel is elevated. 3. Remove: Front brake caliper NO ...

    Troubleshooting method
    The engine operation is not normal and the engine trouble warning light comes on. 1. Check: Fault code number a. Check the fault code number displayed on the FI diagnostic tool. b. Identify the faulty system with the fault code. Refer to "Self-Diagnostic Function table". c. Identi ...

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