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Why do automatics need a brake shift interlock?

  1. Feb 26, 2014 #1
    In automatics,one needs to press the brake (i.e the brake shift interlock switch) to shift the car out of park. What damage would happen if the brake shift-interlock wasn't present. Has it got something to do with the Fottinger fluid clutch? i.e with the automatic "creep" effect?
  2. jcsd
  3. Feb 26, 2014 #2
    Because without it Americans would press the wrong pedal and run over their children.

    See: Audi 100/5000
    Last edited: Feb 26, 2014
  4. Feb 26, 2014 #3


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    As far as I know, it's purely a safety feature - there's really no mechanical reason it has to be present.
  5. Feb 27, 2014 #4
    Because you can't fix stupid....but we do let them have cars.
  6. Feb 27, 2014 #5
    Haha.Nothing beats a clutch pedal though.If only one could control the functioning of the fluid clutch in a automatic with a clutch pedal.Does something like that exist?Automatics feel tasteless for some reason.
    So my idea is to decouple the turbine wheel from the pump wheel when the clutch pedal is pressed,much like the functioning of the hydrodynamic retarder.
  7. Feb 27, 2014 #6


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    To what purpose? All it would achieve would be to basically put the car in neutral whenever the pedal was engaged.
  8. Feb 27, 2014 #7


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    Apparently you haven't been around very long. LOL. Or, I may be giving my age away.
  9. Feb 27, 2014 #8
    Not in Australia.
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