Checking the proper functioning of the brake booster
8 - Vacuum line
070 - Connector
1. Illustrative material for checking the proper functioning of the brake booster is presented in the illustration, to which all references in the text refer.
2. Connect the vacuum gauge (030) to the brake booster (16) and release the vacuum in the vacuum line by pressing the foot brake pedal several times.
3. Connect the tester (051) to the brake caliper.
4. Connect the gauge (060) to the foot brake pedal.
5. Start the engine and by sharply releasing the gas pedal, create the required vacuum in the vacuum line (0.75÷0.80 bar).
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6. If the vacuum drops immediately, or its depth is insufficient, you should check the condition of the sealing ring installed between the vacuum booster servo drive and the master cylinder; it is also possible that the check valve in the vacuum line is out of order. Check the non-return valve (see Section Checking the non-return valve). Replace the defective components.
7. Press the pedal with the required force and read the tester reading. Compare the measurement results with the requirements of the Specifications.
8. Disconnect the gauge (060) from the pedal, disconnect the tester (051) and vacuum gauge (030).
9. Bleed the brake system (see Section Bleeding the brake system).