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I tried to roll my 2005 Civic down an incline, in Neutral, with the engine off and a dead battery, and found that the brakes barely worked, if at all. Why don't the brakes work under these conditions?


(also, i could barely steer, but i expected that, since i know power steering requires the engine to be running...)

regards,
js.

 
Rep Power: 227

The brake pedal is assisted by the brake booster, which requires vacuum generated by the running engine. So when the engine is off, the car is much more difficult to stop with the brake pedal.

 
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Thanks. Does this mean that operating the vehicle in this manner is considered dangerous and thus not recommended?

regards,
js.

 
Rep Power: 227

If you feel that you can't stop the car, then yes it is dangerous.

 
Rep Power: 811

haha i found this out the hard way thinking i could just roll the car out of the garage and down the sloped driveway. and my ebrake sucks too. i had to quickly start the car and mash the brakes before i rolled out in the street too far. stupid brake booster. im guessing it doesnt happen to older cars without this "feature"