Checking the power brake booster
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Depress the brake pedal several times until it feels stiff.
Hold the pedal down. Start the engine. The pedal should travel and feel softer.
Release the brake. switch off the engine. Wait 1 minute. Then depress the pedal. The pedal should still feel soft but should become stiffer when it is depressed several times.
There should be no leakage between the vacuum hose and the terminal at the power brake booster.
There should not be any leakage between the master cylinder and the power brake booster.
Check that the stop lamp functions.
If the stop lamp switch has been modified or changed after installation of the master cylinder and power brake booster it must be readjusted. See Check the shift-lock function .