On-Vehicle Inspection

INSPECT BRAKE BOOSTER
1. Airtightness check.
  1. Start the engine and stop it after 1 or 2 minutes. Depress the brake pedal several times slowly.
    HINT:
    
    If the pedal can be depressed to the floor the first time, but on the 2nd or 3rd time cannot be depressed as far, the booster is airtight.
    
    Fig 1: Depressing Brake Pedal
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Depress the brake pedal while the engine is running, and stop the engine with the pedal depressed.
    HINT:
    
    If there is no change in the pedal reserve distance after holding the pedal for 30 seconds, the booster is airtight.
2. Operating check.
  1. Depress the brake pedal several times with the ignition switch off and check that there is no change in the pedal reserve distance.
  2. Depress the brake pedal and start the engine.
    HINT:
    
    If the pedal goes down slightly, operation is normal.
    
    Fig 2: Identifying Brake Booster Operation
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002