Why do automatics need a brake shift interlock?

  • Thread starter Thread starter marellasunny
  • Start date Start date
  • Tags Tags
    Brake Shift
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
Sign up Log in
7 replies · 2K views
marellasunny
Messages
245
Reaction score
3
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?
 
Physics news on Phys.org
Because without it Americans would press the wrong pedal and run over their children.

See: Audi 100/5000
 
Last edited:
As far as I know, it's purely a safety feature - there's really no mechanical reason it has to be present.
 
Because you can't fix stupid...but we do let them have cars.
 
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.
 
marellasunny said:
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.

To what purpose? All it would achieve would be to basically put the car in neutral whenever the pedal was engaged.
 
marellasunny said:
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?

Apparently you haven't been around very long. LOL. Or, I may be giving my age away.
 
marellasunny said:
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?

Not in Australia.